Utility Vehicle

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No. 2024-061327 filed Apr. 5, 2024, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a utility vehicle including a muffler configured to reduce exhaust noise of the engine.

Description of Related Art

Japanese Patent No. 6655970 discloses a utility vehicle including a cargo box at a back portion of the vehicle body, an engine below the cargo box, and a muffler configured to reduce exhaust noise of the engine.

The above utility vehicle includes a muffler cover attached to and held by the body frame or the muffler to reduce heat transferred from the muffler to the cargo box above the muffler or other components around the muffler. Attaching the muffler cover to the body frame requires the cargo box to be high in position to secure the distance between (i) the muffler cover and engine accessories and (ii) the cargo box, thereby making it difficult to load and unload a cargo. Attaching the muffler cover to the muffler causes the muffler cover to cover the entire muffler and capture heat from the muffler inside, thereby overheating, for example, the surface of the muffler cover. Further, the muffler cover held by the muffler lets rattling noise be made by two or more muffler cover segments bolted to each other.

SUMMARY OF INVENTION

The present invention provides a utility vehicle including a muffler cover that does not require the cargo box to be high in position, that is not overheated, and that causes no rattling noise.

A utility vehicle according to the present invention includes: a body of the utility vehicle; a cargo box at a back portion of the body; an engine below the cargo box; a muffler disposed below the cargo box and configured to reduce exhaust noise of the engine; and a muffler cover covering the muffler and including: an upper cover segment covering an upper portion of the muffler; and a lower cover segment covering a lower portion of the muffler, the upper cover segment and the lower cover segment being separately attached to the muffler and apart from each other.

The above configuration allows the upper and lower cover segments to be attached to and held by the muffler separately and as uncoupled from each other. This allows the muffler cover to cover the muffler without causing rattling noise or requiring the cargo box to be high in position.

With the above configuration, the upper and lower cover segments to be apart from each other by a gap for letting heat from the muffler escape from the muffler cover, preventing heat from remaining inside the muffler cover and thereby preventing the muffler cover from being overheated.

The utility vehicle may preferably be configured such that the upper cover segment has a first length along a length of the muffler which first length is larger than the length of the muffler, and the lower cover segment has a second length along the length of the muffler which second length is smaller than the length of the muffler.

With the above configuration, the upper cover segment covers an upper portion of the muffler over its entire length, whereas the lower cover segment covers a lower portion of the muffler over a length smaller than the entire length of the muffler. The above configuration thus uses the upper cover segment to reduce heat transferred from the muffler upward, for example, to the cargo box, and allows heat to be easily dissipated from the muffler downward to prevent heat from remaining inside the muffler cover.

The utility vehicle may preferably be configured such that the lower cover segment corresponds in position to a portion of the muffler which portion is between a lengthwise center of the muffler and a front end of the muffler.

With the above configuration, the lower cover segment covers a front end portion of the muffler from below which front end portion tends to be heated by exhaust gas from the engine. This inhibits engine accessories below the muffler from being heated by heat dissipated by the muffler.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side view of a utility vehicle.

FIG. 2 is a plan view of an exhaust duct cover, a first muffler cover, and a second muffler cover.

FIG. 3 is a left side view of an exhaust duct cover, a first muffler cover, and a second muffler cover.

FIG. 4 is a perspective view of an exhaust duct and a first muffler.

FIG. 5 is a perspective view of a first exhaust duct cover segment and a second exhaust duct cover segment as detached.

FIG. 6 is a perspective view of a first exhaust duct cover segment and a second exhaust duct cover segment as attached.

FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 2.

FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 2.

FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 2.

FIG. 10 is a perspective view of an upper cover segment and a lower cover segment as detached.

FIG. 11 is a perspective view of an upper cover segment and a lower cover segment as attached.

FIG. 12 is a cross-sectional view taken along line XIII-XIII in FIG. 2.

DESCRIPTION OF THE INVENTION

The description below deals with an example embodiment of the present invention with reference to drawings.

The embodiment described below is a utility vehicle. FIGS. 1 to 3 show arrow F to indicate the forward direction relative to the vehicle body and arrow B to indicate the backward direction relative to the vehicle body. FIGS. 1 and 3 show arrow U to indicate the upward direction relative to the vehicle body and arrow D to indicate the downward direction relative to the vehicle body. FIG. 2 shows arrow L to indicate the leftward direction relative to the vehicle body, which corresponds to the front side of FIG. 1, and arrow R to indicate the rightward direction relative to the vehicle body, which corresponds to the back side of FIG. 1. The lateral direction relative to the body corresponds to the width of the vehicle body.

Overall Configuration of Utility Vehicle

FIG. 1 illustrates a utility vehicle for multiple purposes such as cargo transport and recreation. The utility vehicle includes a body frame 1, a pair of left and right front wheels 2, a pair of left and right rear wheels 3, and a body 4. The front wheels 2 are held by a front portion of the body frame 1, and are turnable and drivable. The rear wheels 3 are held by a back portion of the body frame 1, and are drivable. The utility vehicle includes a driver section 5 disposed at a portion of the body 4 which portion is between the front wheels 2 and the rear wheels 3. The driver section 5 includes a front driver section 5A, a back driver section 5B, and a roll-over protective structure (ROPS) 6 that defines respective driver spaces of the front and back driver sections 5A and 5B. The front driver section 5A includes a driver's seat 7 and a steering wheel 8 for use to change the direction of the front wheels 2. The utility vehicle includes a cargo box 9 and a motor section 10 at a back portion of the body.

Motor Section

The motor section 10 is, as illustrated in FIG. 1, below the cargo box 9 and, as illustrated in FIGS. 2 and 3, includes an engine 11, a continuously variable transmission device 12, and a transmission 13. The continuously variable transmission device 12 is configured to receive motive power from the engine 11 and continuously vary the motive power. The transmission 13 is configured to receive motive power from the continuously variable transmission device 12, adjust the motive power with use of gears, and transmit the resulting motive power to the front and rear wheels 2 and 3. The continuously variable transmission device 12 is coupled to respective lateral portions of the engine 11 and the transmission 13. The continuously variable transmission device 12 includes an endless rotary belt (not illustrated in the drawings) and belt pulleys (not illustrated in the drawings) each with an adjustable belt winding diameter to vary received motive power. The transmission 13 is backward of the engine 11.

As illustrated in FIG. 2, the motor section 10 includes an exhaust duct 14 extending from the engine 11, a first muffler 15 connected to the exhaust duct 14, and a second muffler 16 connected to the first muffler 15. As illustrated in FIG. 3, the second muffler 16 includes two attachment sections 16b at a lower back portion. The transmission 13 includes a support 13a with which the attachment sections 16b are locked. The transmission 13 holds a back portion of the second muffler 16. The engine 11 discharges exhaust gas through the exhaust duct 14 into the first muffler 15, which cleans the exhaust gas with use of a catalyst and discharges the resulting exhaust gas into the second muffler 16, which discharges the exhaust gas through a discharge cylinder 16a (see FIGS. 2 and 3) while muffling exhaust noise.

Exhaust Duct The exhaust duct 14, as illustrated in FIGS. 2 and 4, includes (i) two upstream exhaust duct sections 17 connected to respective exhaust sections 11a of the engine 11 and (ii) a downstream exhaust duct section 18 merging the upstream exhaust duct sections 17 with each other and connecting the upstream exhaust duct sections 17 to the first muffler 15 and provided with a CO₂ sensor 19 configured to detect carbon dioxide discharged from the engine 11.

The upstream exhaust duct sections 17 extend from the respective exhaust sections 11a forward relative to the body, then leftward relative to the body along its width, and then backward relative to the body in the front-back direction (hereinafter referred to as “lengthwise”) relative to the body to reach the downstream exhaust duct section 18. The upstream exhaust duct sections 17 are arranged vertically relative to the body. The upstream exhaust duct sections 17, specifically, each include (i) a starting end portion 17a and a terminal end portion 17b each extending lengthwise relative to the body and (ii) an intermediate portion 17c interposed between the starting and terminal end portions 17a and 17b and extending widthwise relative to the body. The intermediate portion 17c and terminal end portion 17b of each upstream exhaust duct section 17 are arranged vertically relative to the body. The upstream exhaust duct sections 17 may alternatively be arranged lengthwise or widthwise relative to the body.

As illustrated in FIG. 3, the downstream exhaust duct section 18 is backward of the upstream exhaust duct sections 17 and extends lengthwise relative to the body.

Exhaust Duct Cover and First Muffler Cover As illustrated in FIGS. 2 and 3, the motor section 10 includes an exhaust duct cover 20 covering the exhaust duct 14 and configured to reduce the amount of heat that the exhaust duct 14 dissipates and that is transferred to, for example, the cargo box 9. The motor section 10 includes a first muffler cover 21 covering the first muffler 15 and configured to reduce the amount of heat that the first muffler 15 dissipates and that is transferred to, for example, the cargo box 9. As illustrated in FIGS. 2, 3, and 11, the motor section 10 includes a second muffler cover 22 covering the second muffler 16 and configured to reduce the amount of heat that the second muffler 16 dissipates and that is transferred to, for example, the cargo box 9.

As illustrated in FIGS. 2 and 3, the exhaust duct cover 20, which covers the exhaust duct 14, covers both the upstream exhaust duct sections 17 and the downstream exhaust duct section 18. The exhaust duct cover 20 for the present embodiment covers only the intermediate portion 17c and terminal end portion 17b of each upstream exhaust duct section 17 and the entire downstream exhaust duct section 18. The exhaust duct cover 20 may alternatively cover the entire upstream exhaust duct sections 17.

The exhaust duct cover 20, as illustrated in FIGS. 3 and 5, includes two exhaust duct cover segments 23 opposite to each other across the diameter of each of the upstream exhaust duct sections 17 and the downstream exhaust duct section 18. The exhaust duct cover 20 for the present embodiment includes a pair of upper and lower exhaust duct cover segments 23 opposite to each other across the diameter of each of the upstream exhaust duct sections 17 and the downstream exhaust duct section 18.

The description below assumes that the exhaust duct cover 20 includes a first exhaust duct cover segment 23a and a second exhaust duct cover segment 23b.

As illustrated in FIG. 3, the first exhaust duct cover segment 23a covers the upstream and downstream exhaust duct sections 17 and 18 from above, whereas the second exhaust duct cover segment 23b covers the upstream and downstream exhaust duct sections 17 and 18 from below. The first exhaust duct cover segment 23a has an opening through which the CO₂ sensor 19 protrudes.

As illustrated in FIGS. 3 and 5, the first muffler cover 21, which covers the first muffler 15, includes two muffler cover segments 24 opposite to each other across the diameter of the first muffler 15. The first muffler cover 21 for the present embodiment includes a pair of upper and lower muffler cover segments 24 opposite to each other across the diameter of the first muffler 15.

The description below assumes that the first muffler cover 21 includes a first muffler cover segment 24a and a second muffler cover segment 24b.

As illustrated in FIG. 3, the first muffler cover segment 24a covers the first muffler 15 from above, whereas the second muffler cover segment 24b covers the first muffler 15 from below. As illustrated in FIGS. 3, 5, and 6, the first muffler 15 includes an exhaust port 15a, and the second muffler cover segment 24b has a back portion provided with an exhaust port cover 24c integral with the second muffler cover segment 24b and covering the exhaust port 15a from below.

As illustrated in FIG. 4, the first muffler cover segment 24a is integral with the first exhaust duct cover segment 23a, whereas the second muffler cover segment 24b is integral with the second exhaust duct cover segment 23b.

The exhaust duct cover 20 and the first muffler cover 21 are attached respectively to the exhaust duct 14 and the first muffler 15 on the basis of a structure illustrated in drawings such as FIG. 5.

The motor section 10, as illustrated in FIG. 5, includes a first support 25 attached to the upstream exhaust duct sections 17, a second support 26 attached to the downstream exhaust duct section 18, and a third support 27 attached to the exhaust port 15a of the first muffler 15.

Specifically, as illustrated in FIGS. 3 and 6, the first support 25 is a ring around the respective intermediate portions 17c of the upstream exhaust duct sections 17. The first support 25 includes two arch-shaped first support segments including respective couplers 25a welded to the intermediate portions 17c, so that the first support 25 is held by the upstream exhaust duct sections 17 with use of the couplers 25a.

As illustrated in FIGS. 4 and 7, the second support 26 is a ring around the downstream exhaust duct section 18, and includes two arch-shaped second support segments including respective couplers 26a welded to the downstream exhaust duct section 18, so that the second support 26 is held by the downstream exhaust duct section 18 with use of the couplers 26a.

As illustrated in FIGS. 4 and 9, the third support 27 is a ring around the exhaust port 15a of the first muffler 15, and includes two arch-shaped third support segments including respective couplers 27a welded to the exhaust port 15a, so that the third support 27 is held by the first muffler 15 with use of the couplers 27a.

As illustrated in FIGS. 2 and 3, the motor section 10 includes a first fastening band 31 and a second fastening band 32 each serving to attach the exhaust duct cover 20 to the exhaust duct 14 and a third fastening band 33 serving to attach the first muffler cover 21 to the first muffler 15. The exhaust duct cover 20 and the first muffler cover 21 are attached respectively to the exhaust duct 14 and the first muffler 15 as illustrated in FIGS. 2, 3, 7, 8, and 9.

Specifically, the first exhaust duct cover segment 23a is placed above the upstream exhaust duct sections 17 and the downstream exhaust duct section 18 to bring an inner side portion into contact with the first and second supports 25 and 26, so that the first exhaust duct cover segment 23a is supported by the first and second supports 25 from inward. The second exhaust duct cover segment 23b is placed below the upstream exhaust duct sections 17 and the downstream exhaust duct section 18 to bring an inner side portion into contact with the first and second supports 25 and 26, so that the second exhaust duct cover segment 23b is supported by the first and second supports 25 from inward.

As illustrated in FIG. 7, the first fastening band 31 is fitted around respective portions of the first and second exhaust duct cover segments 23a and 23b which portions correspond to the first support 25 and is fastened with use of a fastening screw 31a to fix the first and second exhaust duct cover segments 23a and 23b to the first support 25. As illustrated in FIG. 8, the second fastening band 32 is fitted around respective portions of the first and second exhaust duct cover segments 23a and 23b which portions correspond to the second support 26 and is fastened with use of a fastening screw 32a to fix the first and second exhaust duct cover segments 23a and 23b to the second support 26. The exhaust duct cover 20 is attached to the exhaust duct 14 with use of the first and second fastening bands 31 and 32 and the first and second supports 25 and 26. As illustrated in FIGS. 6, 7, and 8, the first exhaust duct cover segment 23a is provided with two fixing members 28 for fixing the respective first and second fastening bands 31 and 32 from outward to prevent displacement.

The first muffler cover segment 24a is placed above the first muffler 15 to bring an inner side portion into contact with the third support 27, so that the first muffler cover segment 24a is supported by the third support 27 from inward. This placement is simultaneous with the placement of the first exhaust duct cover segment 23a above the upstream exhaust duct sections 17 and the downstream exhaust duct section 18 to be supported by the first and second supports 25 and 26. The second muffler cover segment 24b is placed below the first muffler 15 to bring an inner side portion into contact with the third support 27, so that the second muffler cover segment 24b is supported by the third support 27 from inward. This placement is simultaneous with the placement of the second exhaust duct cover segment 23b below the upstream exhaust duct sections 17 and the downstream exhaust duct section 18 to be supported by the first and second supports 25 and 26.

As illustrated in FIGS. 2, 3, and 9, the third fastening band 33 is fitted around respective portions of the first and second muffler cover segments 24a and 24b which portions correspond to the third support 27 and is fastened with use of a fastening screw 33a (see FIG. 8) to fix the first and second muffler cover segments 24a and 24b to the third support 27. The first muffler cover 21 is attached to the first muffler 15 with use of the second and third fastening bands 32 and 33 and the second and third supports 26 and 27. As illustrated in FIGS. 6 and 9, the first muffler cover segment 24a is provided with a fixing member 29 for fixing the third fastening band 33 from outward to prevent displacement.

Second Muffler Cover

As illustrated in FIG. 10, the second muffler cover 22, which covers the second muffler 16, includes an upper cover segment 35 and a lower cover segment 36.

As illustrated in FIGS. 11 and 12, the upper cover segment 35 extends circumferentially around an upper portion of the second muffler 16. As illustrated in drawings such as FIGS. 10 and 12, the second muffler 16 has an upper circumferential portion provided with two or more upper cover supports 37 to which the upper cover segment 35 is attached with use of respective coupling bolts 38. The upper cover segment 35 is held by the second muffler 16 in such a manner as to cover an upper portion of the second muffler 16.

As illustrated in FIGS. 3 and 12, the lower cover segment 36 is below a lower portion of the second muffler 16. As illustrated in drawings such as FIGS. 10 and 12, the second muffler 16 has a lower circumferential portion provided with two or more lower cover supports 39 to which the lower cover segment 36 is attached with use of respective coupling bolts 40. The lower cover segment 36 is held by the second muffler 16 in such a manner as to cover a lower portion of the second muffler 16.

As illustrated in FIG. 12, the upper and lower cover segments 35 and 36 are separately attached to the second muffler 16 with gaps 41 between the upper and lower cover segments 35 and 36 which gaps 41 serve to let heat dissipated by the second muffler 16 escape from the second muffler cover 22.

As illustrated in FIG. 2, the upper cover segment 35 has a length L1 along the length of the second muffler 16, whereas the second muffler 16 has a length L2, the length L1 being larger than the length L2. The lower cover segment 36 has a length L3 along the length of the second muffler 16 which length L3 is smaller than the length L2. The upper cover segment 35 covers the second muffler 16 over its entire length, whereas the lower cover segment 36 covers the second muffler 16 over a length smaller than the entire length of the second muffler 16.

As illustrated in FIG. 2, the lower cover segment 36 corresponds in position to a portion of the second muffler 16 which portion is between its lengthwise center C and its front end. The lower cover segment 36 covers a front end portion of the second muffler 16 from below which front end portion tends to be heated by exhaust gas from the engine 11.

Alternative Embodiments

(1) The embodiment described above is an example in which the upper cover segment 35 has a length L1 larger than the length L2 of the second muffler 16. The present invention is, however, not limited to such a configuration: The length L1 may be equal to or smaller than the length L2.

(2) The embodiment described above is an example in which the lower cover segment 36 has a length L3 smaller than the length L2 of the second muffler 16. The present invention is, however, not limited to such a configuration: The length L3 may be larger than or equal to the length L2.

(3) The embodiment described above is an example in which the lower cover segment 36 is between the center C of the second muffler 16 and its front end. The present invention is, however, not limited to such a configuration: The lower cover segment 36 may be between the center C of the second muffler 16 and its back end.

(4) The embodiment described above includes a first muffler 15, but may alternatively exclude the first muffler 15.

(5) The embodiment described above includes an exhaust duct cover 20 and a first muffler cover 21, but may alternatively exclude the exhaust duct cover 20 and the first muffler cover 21.

INDUSTRIAL APPLICABILITY

The present invention is applicable to any utility vehicle including a cargo box, an engine below the cargo box, and a second muffler.

REFERENCE SIGNS LIST

• • 9 Cargo box
  • 11 Engine
  • 16 Second muffler (muffler)
  • 22 Second muffler cover (muffler cover)
  • 35 Upper cover segment
  • 36 Lower cover segment
  • C Center
  • L1 Length of upper cover segment
  • L2 Length of second muffler
  • L3 Length of lower cover segment