JP6766729B2 - Work vehicle - Google Patents

Description

The present invention relates to a work vehicle such as an agricultural tractor, and more particularly to a brake interlocking configuration including a parking brake.

Conventionally, in the braking device of an agricultural tractor, the left and right brake operating rods are arranged on both sides of the mission case, the front part is connected to the brake pedal, and the rear part is left and right, as a configuration for connecting to both the parking lever and the brake pedal. It is configured to be connected to the brake mechanism, a lateral interlocking shaft is arranged below the mission case, and the lower part of the arm whose upper part is connected to the brake operating rod is pivotally attached to the lateral interlocking shaft, and the operation arm connected to the parking lever is attached. When the operating arm is operably connected to the brake operating rod on one side and the operating arm is operated to the braking side by the parking lever, the operating force is transmitted to the brake operating rod on the one side, and this operating force is applied to the lateral interlocking shaft and the lateral interlocking shaft. It is configured to be transmitted to brake the brake operating rod on the other side via the operation arm on the other side (Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-273367

According to the configuration of Patent Document 1, the two operating systems can be arranged separately at separate positions while avoiding the centralized arrangement of the brake pedal and the parking lever, but since the lateral interlocking shaft is arranged below the mission case, there is a risk of damage. In addition, the configuration is complicated because the connecting means for operating one of the brake brake operating rods from the parking lever is long.

The present invention has taken the following technical measures to solve the above problems.

According to the first aspect of the present invention, brake actuating rods 26L and 26R for braking the left and right brake mechanisms 17L and R in conjunction with the stepping operation of the brake pedals 28L and 28R are arranged on the left and right sides of the mission case 5. Arm connecting mechanisms 25L and 25R are provided so that the brake operating rods 26L and 26R and the operating arms 24L and 24R that interlock the brake mechanisms 17L and 17R can be interlocked.
In a work vehicle in which a parking lever 35 is arranged on the upper side of the mission case 5 and the arm connecting mechanisms 25L and 25R are interlocked with the parking levers 35 via the parking connecting mechanisms 38L and 38R, the parking connecting mechanism 38L , 38R is provided with a plurality of fulcrum shafts 43 and 44, the first fulcrum shaft 43 of the plurality of fulcrum shafts is interlocked with the parking lever 35, and the second fulcrum shaft 44 is extended over the left and right width of the mission case 5. The work vehicle is linked and connected to the left and right arm connecting mechanisms 25L and 25R, respectively.

The invention according to claim 2 is the invention according to claim 1, wherein the parking connection mechanisms 38L and 38R each include a plurality of interlocking rods 39 and 40 and a plurality of link mechanisms 41 and 42, respectively. The fulcrum shafts 43 and 44 are arranged at predetermined intervals in the front-rear direction.
The parking lever 35 and the first fulcrum shaft 43 are interlocked by the first interlocking rod 39, the second fulcrum shaft 44 and the arm linking mechanism 25 are interlocked by the second interlocking rod 40, and the first fulcrum shaft 43 and the first fulcrum shaft 43 are interlocked. The two fulcrum shafts 44 are interlocked and connected by the first link mechanism 41.
The second interlocking rod 40 is configured to reciprocate substantially along the rod direction by rotating the second fulcrum shaft 44.

The invention according to claim 3 is the invention according to claim 2, wherein the arm connecting mechanisms 25L and 25R connect and support the operating arm 24 on the brake mechanism 17 side and the brake operating rod 26, respectively. A relay arm 32 that rotates around a shaft 33 is provided, and the relay arm 32 and the second interlocking rod 40 are interlocked and connected by a second link mechanism 42, and by an operation substantially along the rod direction of the second interlocking rod 40. The relay arm 32 is rotated so that the brake operating rod 26 is interlocked with the braking side of the brake mechanism 17.

According to a fourth aspect of the present invention, in the third aspect, the second link mechanism 42 is integrally provided with an interlocking pin 46 inserted and fixed to the lower end side of the second interlocking rod 40 and the relay arm 32. A driven relay arm portion 32a is provided, and the interlocking pin 46 is provided so as to penetrate through an elongated hole 32b formed at an end portion of the driven relay arm portion 32a.

According to a fifth aspect of the present invention, in the fourth aspect, the lower limit position of the interlocking pin 46 on the lower end side of the second interlocking rod 40 is adjustable along the rod rod body.

According to the invention of claim 1, the left and right brake actuating rods 26L, 26R are configured to operate the actuating arms 24L, 24R interlocking the left and right brake actuating mechanisms 17L, 17R via the arm connecting mechanisms 25L, 25R. When the arm connecting mechanisms 25L and 25R are interlocked with the parking lever 35, a plurality of fulcrum shafts 43 and 44 interlocking with a plurality of fulcrum shafts 43 and 44 intervening in the middle are arranged apart from each other in the front-rear direction and a mission. Since it is arranged in the upper part of the case 5, it is less damaged and can be assembled by utilizing the empty space in the upper part of the mission case 5.

According to the inventions of claims 2 to 4, in addition to the effect of claim 1, the plurality of fulcrum shafts 43 and 44 are arranged at predetermined intervals in the front-rear direction and the rotation of the second fulcrum shaft 44. Since the second interlocking rod 40 is configured to reciprocate substantially along the rod direction, the allowable space for arrangement is small due to the arrangement of various accessories such as hydraulic pipes and various valves on the side surface of the mission case 5. However, it is sufficient to secure an allowable space substantially along the rod direction of the second interlocking rod 40, and a degree of freedom in design can be secured.

According to the invention of claim 5, in addition to the effect of claim 4, the initial position and operating amount of the relay arm 32 are adjusted by adjusting the lower limit position of the interlocking pin 46 having a different diameter in the second interlocking rod 40. However, the relationship between the amount of operation by the parking lever 35 and the braking force can be adjusted, but due to the relationship between the interlocking pins 46 having different diameters with respect to the second interlocking rod 40, the adjustment work is performed from the side surface of the machine body 1. It is easy to carry out, and even if the rear wheel 3 is mounted, it can be carried out without any problem.

It is a side view of an agricultural tractor. It is a top view of a mission case. It is a side view which shows the mission case and the peripheral structure. (A) is a perspective view showing a right side brake interlocking mechanism, and (B) is a perspective view showing a left side brake interlocking mechanism. It is a side view which shows the parking connection mechanism. (A) is a rear view showing a parking connection mechanism, and (B) is a bottom view thereof. It is a perspective view which shows the parking connection mechanism. (A) is an enlarged front view showing a parking connection mechanism, and (B) is an enlarged side view thereof. It is sectional drawing which shows the waterproof structure of the actuating arm part of a brake mechanism.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

Agricultural tractors as work vehicles work in fields or the like while self-propelled by power. Agricultural tractors include left and right front wheels 2L and 2R that are on the front side of the fuselage 1 and can be driven and steered, left and right rear wheels 3L and 3R mounted on the rear side of the fuselage 1, and an engine 4 as a power source. A transmission case 5 in which a transmission is installed is provided. In the pair of left and right members, the reference numeral L in the figure indicates the left side, and the symbol R indicates the right side.

Further, a connecting device 7 to which a working machine 6 such as a rotary can be mounted is arranged at the rear part of the machine body 1. The connecting device 7 is a three-point link composed of a top link 7a in the upper center and lower links 7b and 7b in the lower left and right, and by hydraulically rotating the lift arm 8, the lower link is via the lift rods 9 and 9. It is configured to rotate 7b and move the working machine 6 up and down.

The tractor 1 is covered with a cabin 11 around the cockpit 10 on the fuselage. Inside the cabin 11, the steering handle 13 is erected from the dashboard 12 on the front side of the driver's seat 10, and various operation pedals such as the clutch pedal 14, the brake pedal, the accelerator pedal, and the forward / backward lever are placed around the driver's seat 10. Various operation levers such as a speed change lever are arranged.

A transmission mechanism is arranged in the mission case 5. Regarding the transmission mechanism, the power from the engine 4 is transmitted to the rear wheel differential mechanism 15 via the known forward / backward switching mechanism, main transmission mechanism, and auxiliary transmission mechanism, and is transmitted to the left and right ends of the left and right differential output shafts 16L and 16R. It is equipped with brake mechanisms 17L and 17R. The final reduction mechanism 19L, 19R by combining spur gears is formed between the left and right differential output shafts 16L, 16R and the rear axles 18L, 18R that support the left and right rear wheels 3L, 3R.

Details of the configuration of the left and right brake mechanisms 17L and 17R and the interlocking configuration will be described. Since the left and right brake mechanisms 17L and 17R have a common configuration, the reference numeral L meaning the left side and the reference numeral R meaning the right side will be omitted as appropriate. The brake mechanism 17 is provided with a pair of brake disc groups 20a and 20b that are fitted to the differential output shaft 16 and are slidable in the axial direction, and a pair of brake cam discs are provided between the pair of brake disc groups 20a and 20b. 21a and 21b are provided, and a cam mechanism 22 composed of a cam groove and a ball is formed between the pair of brake cam discs 21a and 21b. The pair of brake cam discs 21a and 21b are provided with protrusions 21c and 21d on the front side, and the brake cam discs 21a and 21b are attached to each other by pulling the intermediate portion of the cam operating link 23 connecting the two protrusions 21c and 21d forward. The brake disc groups 20a and 20b are both rotated in the opposite direction and expanded by the cam mechanism 22 so that they can be pressed against the fixed wall portion to brake the differential output shaft 16.

The actuating arm 24 is connected to the central portion of the cam actuating link 23 of the brake mechanism 17, and is connected to the brake actuating rod 26 extending forward along the side surface of the transmission case 5 via the relay arm connecting mechanism 25. The front end of the brake operating rod 26 is connected to the L-shaped arm 27 supported on the side surface of the transmission case 5, and the L-shaped arm 27 is rotated clockwise in FIG. 3 in conjunction with the depression of the brake pedal 28 to brake. The actuating rod 26 is pulled forward, and the brake mechanism 17 is actuated to the braking side via the arm connecting mechanism 25 and the actuating arm 24. A pair of left and right brake pedals 28 are provided so that the left and right brake mechanisms 17L and 17R can be braked independently, and the left brake interlocking rod 27L and the right brake interlocking rod 27R can be operated.

The arm connecting mechanism 25 will be described. As shown in FIG. 4, a support plate 30 is detachably fastened to a rear axle case 29 accommodating the differential output shaft 16, the brake mechanism 17, the rear axle 18, the final deceleration mechanism 19, and the like, and the support plate 30 is detachably fastened. A U-shaped connecting piece 24a is provided at the front end of the operating arm 24 through which the through hole 30a is formed. On the other hand, a U-shaped connecting piece 26a is provided at the rear end of the brake operating rod 26, and these two U-shaped connecting pieces 24a and 26a are rotatably connected to each other. In addition, the connecting pin 31 that connects the two penetrates the relay arm 32 that is interlocked with the parking connecting mechanism for the parking lever, which will be described later. The relay arm 32 is rotatably provided around a fulcrum pin 33 connected to the support plate 30. That is, the boss portion 32a of the relay arm 32 is loosely fitted to the fulcrum pin 33 and is rotatably provided around the fulcrum pin 33. Therefore, the U-shaped connecting piece 26a and the relay arm 32 of the brake operating rod 26 constituting the arm connecting mechanism 25 are configured to pull the operating arm 24 and brake the brake mechanism 17 by operating them in a predetermined manner. Is. The left and right brake mechanisms 17L and 17R are configured separately from the connecting mechanisms 25L and 25R, respectively, so that the left and right brake mechanisms 17L and 17R can be braked independently.

Next, the braking configuration by the parking lever 35 will be described with reference to FIGS. 3 and 5 to 8. The parking lever 35 is rotatably supported by a support shaft 37 on one side (right side in the drawing) of the seat bracket 36 arranged above the mission case 5. The parking lever 35 is configured to be rotatable around the support shaft 37, but when the grip portion 35a is raised and operated, the relay arm 32 of the connection mechanism 25 is interlocked with the relay arm 32 via the parking connection mechanism 38 to provide a brake mechanism. 17 is configured to be able to operate on the braking side.

Regarding the parking connection mechanism 38, two interlocking rods 39, 40, and a first link mechanism 41 interposed between the two interlocking rods 39, 40, between the parking lever 35 and the relay arm 32 of the arm connection mechanism 25, A second link mechanism 42 or the like interposed between the lower interlocking rod 40 (second interlocking rod) and the relay arm 32 is arranged. The upper end of the upper interlocking rod 39 (first interlocking rod) is connected between the support shaft 37 of the parking lever 35 and the grip portion 35a. The first link mechanism 41 includes a front upper fulcrum shaft 43 (first fulcrum shaft) and a rear lower fulcrum shaft 44 (second fulcrum shaft) on the upper side of the mission case 5 inside the seat bracket 36. The parallel link 45 is configured so as to connect between the two fulcrum shafts 43 and 44, and the extension arm portion 45b provided by extending to the parallel link arm 45a provided on the fulcrum shaft 43 side is provided with the upper interlocking rod 39 (the upper interlocking rod 39 (the first). 1 Connect the lower ends of the interlocking rod). On the other hand, the lower interlocking rod 40 (second interlocking rod) is connected to the arm portion 45d which is extended to the parallel link arm 45c provided on the fulcrum shaft 44 (second fulcrum shaft) side. Regarding the lower end side of the lower interlocking rod 40 (second interlocking rod), an interlocking pin 46 having a different diameter having a through hole is inserted into the lower interlocking rod 40 (second interlocking rod), and at the lower part thereof. Is formed by screwing a long screw nut 50 and a fixing nut 51 into a lower interlocking rod 40 (second interlocking rod) in this order. Of these, the small diameter portion 46a on the tip side of the interlocking pin 46 having a different diameter is penetrated through the elongated hole 32b formed at the end of the driven relay arm portion 32a provided integrally with the relay arm 32 to prevent it from coming off. The two-link mechanism 42 is used. That is, the second link mechanism 42 is provided with a boss portion 32c that rotatably and freely fits the relay arm 32 around the fulcrum pin 33 and an extension of the boss portion 32c in the rearward direction of the machine body 1. It is composed of the driven relay arm portion 32a and the interlocking pin 46 having a different diameter. Since the elongated hole 32b is formed in the driven relay arm portion 32a along the vertical direction so as to penetrate the interlocking pin 46 having a different diameter, the operation of the brake braking side on the brake operating rod 26 side causes the above-mentioned operation. Even if the relay arm 32 is actuated on the braking side (rotational action around the fulcrum pin 33), the actuating force is not transmitted to the interlocking rod 40 and other parking coupling mechanism 38 sides.

The long screw nut 50 and the fixing nut 51 can be loosened and appropriately adjusted along the rod body, but this adjusted position is the lower limit position of the interlocking pin 46 having a different diameter. Therefore, the braking operation is performed by pulling up the interlocking rod 40, and the braking timing, braking force, and the like can be adjusted by adjusting the lower limit position thereof. The left and right braking force can be easily balanced. Specifically, the position of the interlocking pin 46 having a different diameter with respect to the elongated hole 32b of the driven relay arm portion 32a is determined by reversing the long screw nut 50 in the forward and reverse directions, and is set by the fixing nut 48. .. The position of the elongated hole 32b, and thus the position of the relay rod 32, can be set in combination with the adjustment of the stepping allowance of the brake pedal 28, etc., although it is affected by the relationship with the brake interlocking rod 26.

Of the fulcrum shafts 43 and 44, the fulcrum shaft 44 (second fulcrum shaft) on the lower rear side is provided so as to extend to the opposite side (left side in the illustration) on the upper surface of the mission case 5, and is provided on the lower side. The configurations below the interlocking rod 40 (second interlocking rod) are symmetrically provided in pairs, and are configured to brake the left brake mechanism 17L configured on the opposite side (left side). More specifically, the base bracket 47 that extends substantially across the left and right widths of the case 5 is detachably fixed to the upper surface of the mission case 5, and an upright support portion 47a is formed on one side of the left and right sides (right side in the drawing) to support the case. Of the shafts 43 and 44, the fulcrum shaft 43 (first fulcrum shaft) on the front upper side is supported. The support shaft 43 has a fixed shaft shape fixed to the standing support portion 47a so that the axis is horizontal, and the first boss portion 45A provided with the parallel link arm 45a and the arm 45b is rotatably loosely fitted. It is provided. Further, the other support shaft 44 (second fulcrum shaft) is detachably attached to the base bracket 47 with a pair of bracket members 49a and 49a and is rotatably fitted to a fixed cylinder shaft 49 provided horizontally. It is provided. At both ends of the fulcrum shaft 44 (second fulcrum shaft), the parallel link arm 45c and the arm portion 45d extending to the parallel link arm 45c are attached to the lower fulcrum shaft 40 (second fulcrum shaft 40) of the left and right brake mechanisms 17L and 17R. It is provided on each of the left and right ends of the interlocking rod).

Since it has the above configuration, when the direction is adjusted or the headland is turned while the field work is being carried out, one of the left and right brake pedals 28L and 28R is stepped on to brake the brake mechanisms 17L and 17R on the corresponding side. However, when the brake pedal 28 is depressed, the operating arm 24 is pulled and operated via the L-shaped arm 27 and the brake operating rod 26, so that the brake mechanism 17 is put into a braking state. At the same time, the relay arm 32 rotates forward along with the brake operating rod 26 and the operating arm 24, but as described above, since the elongated hole 32c is formed in the driven relay arm portion 32a, the relay arm 32 The parking lever 35 is not operated indiscriminately because it is not affected by the movement of the rod 40 and is not transmitted to the other parking connecting mechanism 38 side of the interlocking rod 40.

On the other hand, when the aircraft 1 is stopped, the parking lever 35 is pulled up to prevent unexpected movement. The relay arm 32 can be rotated via the parking connection mechanism 38 to operate the operating arm 24 on the braking side. That is, by the rotation of the parking lever 35, the upper interlocking rod 39 (first interlocking rod) is pulled up, and the lower interlocking rod 40 (second interlocking rod) is pulled up via the parallel link 45. The upper interlocking rod 39 (first interlocking rod) and the lower interlocking rod 40 (second interlocking rod) are both provided with an upward pulling force along the axis of the rod, and are parallel to each other. By interposing the link 45, the rods can be displaced back and forth and arranged, and the interlocking rods 39 and 40 can be rationally arranged in a place where the installation space is restricted. The upper interlocking rod 39 (the upper interlocking rod 39) with respect to the connection point p of the upper interlocking rod 39 (first interlocking rod) with the parking lever 35 and the bracket portion 45b extending to the parallel link bracket 45a provided on the fulcrum shaft 43 side. The connection points q at the lower end of the first interlocking rod) are arranged substantially vertically vertically, and the reciprocating swing motion range of the parallel link 45 is set to be substantially in the vertical direction for both the connection points p and q. This is because the rod 39 moves up and down substantially in the longitudinal direction, and the amplitude in the front-back direction can be set to be extremely small. Similarly, the connection point r of the parallel link bracket 45c to the bracket portion 45d of the lower interlocking rod 40 (second interlocking rod) is abbreviated as the connection point s of the interlocking pin 46 having a different diameter with the driven relay arm portion 32a. Arranged in a vertical vertical relationship, the lower interlocking rod 40 can move up and down substantially in the longitudinal direction.

At the lower end side of the lower interlocking rod 40 (second interlocking rod), the interlocking pin 46 having a different diameter engages with the upper portion of the elongated hole 32b formed at the end of the driven bracket portion 32a and is driven. The bracket portion 32a is rotated, and the relay arm 32 is rotated to the brake braking side (front side in the figure). The brake operating rod 26 connected by the rotation of the relay arm 32 is pushed to the front side, but a long hole 26b is formed in the U-shaped connecting piece 26a connecting the L-shaped arm 27 and the brake operating rod 26. The brake operating rod 26 is configured so that it is not transmitted to the L-shaped arm 27 even if it is pushed forward as described above.

In the interlocking rod 40 (second interlocking rod) on the lower side of the parking coupling mechanism 38, the position of the interlocking rod 40 of the interlocking pin 46 having a different diameter is set by the long screw nut 50 and the fixing nut 51. ing. By adjusting the fixed position of the screw nut 50 with respect to the interlocking rod 40, the engagement state between the interlocking pin 46 having a different diameter and the relay arm portion 32a can be adjusted, and the brake braking force when the parking lever 35 is pulled up can be adjusted appropriately. it can. As the length adjusting means, in addition to the case where it is configured at the lower end of the interlocking rod 40, a length adjusting means such as a turnbuckle may be provided in the middle portion of the interlocking rod 40, and the braking braking force can be adjusted. is there. By the way, in the case of the above embodiment, since the long screw nut 50 and the fixing nut 51 are arranged at the lower end of the interlocking rod 40, even after the rear wheel 3 tires are mounted. The adjustment work is easy because, for example, tools from the lower side of the machine body 1 can be brought close to each other without removing the tire.

FIG. 9 shows an improved plan for the mudproof and waterproof configuration of the operating arm 24 of the brake mechanism 17. Flexible boots 54 made of rubber or the like are attached for the purpose of preventing mud and waterproofing. Specifically, the flexible boot 54 is inserted into the through hole 30a of the support plate 30 from the rear to the front, and the rear end flange portion 54a is fitted around the through hole 30b of the support plate 30 with the same outer diameter. It is configured to form a hole 30b and mount it so that it can be positioned.

Further, the front end side of the operating arm 24 is shown, an O-ring 55 is interposed between the flexible boot 54 and the operating arm 24, and a collar 56 and a fixing nut 57 are provided to prevent the boot tip from being displaced or worn. As a result, oil leakage can be prevented.

5 Mission case 17L, 17R Brake mechanism 25L, 25R Arm linking mechanism 26L, 26R Brake operating rod 28L, 28R Brake pedal 32 Relay arm 32a Driven relay arm 32b Long hole 35 Parking lever 38L, 38R Parking linking mechanism 39 First interlocking rod 40 2nd interlocking rod 41 1st link mechanism 42 2nd link mechanism 43 1st fulcrum shaft 44 2nd fulcrum shaft 46 (different diameter) interlocking pin

Claims (5)

Brake actuating rods (26) that brake the left and right brake mechanisms (17) in conjunction with the depression operation of the brake pedal (28) are arranged on the left and right sides of the transmission case (5) to form a brake actuating rod (26). An arm connecting mechanism (25) is provided so as to be interlocked with an operating arm (24) that interlocks with the brake mechanism (17), and a parking lever (35) is arranged on the upper side of the mission case (5). In a work vehicle configured to interlock and operate the arm connecting mechanism (25) via the parking connecting mechanism (38), the parking connecting mechanism (38) is provided with a plurality of fulcrum shafts (43, 44). The first fulcrum shaft (43) is interlocked with the parking lever (35), and the second fulcrum shaft (44) is extended over the left and right widths of the mission case (5) to connect the left and right arms, respectively. A work vehicle linked to (25). The parking connection mechanism (38) includes a plurality of interlocking rods (39, 40) and a plurality of link mechanisms (41, 42), respectively, and the plurality of fulcrum shafts (43, 44) are separated from each other by a predetermined distance in the front-rear direction. The parking lever (35) and the first fulcrum shaft (43) are interlocked by the first interlocking rod (39), and the second fulcrum shaft (44) and the arm linking mechanism (25) are secondly interlocked. The rod (40) is interlocked, the first fulcrum shaft (43) and the second fulcrum shaft (44) are interlocked and connected by the first link mechanism (41), and the second fulcrum shaft (44) is rotated to the second. The work vehicle according to claim 1, wherein the interlocking rod (40) is configured to reciprocate substantially along the rod direction. The arm connecting mechanism (25) connects the operating arm (24) on the brake mechanism (17) side and the brake operating rod (26), respectively, and a relay arm (relay arm) that rotates around a support shaft (33). 32), the relay arm (32) and the second interlocking rod (40) are interlocked and connected by a second link mechanism (42), and the second interlocking rod (40) is operated substantially along the rod direction. The work vehicle according to claim 2, wherein the relay arm (32) is rotated so that the brake operating rod (26) is interlocked with the braking mechanism (17) on the braking side. The second link mechanism (42) has an interlocking pin (46) inserted and fixed to the lower end side of the second interlocking rod (40), and a driven relay arm portion (32a) provided integrally with the relay arm (32). 3. The work vehicle according to claim 3, wherein the interlocking pin (46) is provided through a long hole (32b) formed at an end of the driven relay arm portion (32a). The work vehicle according to claim 4, wherein the lower limit position of the interlocking pin (46) is adjustedably provided along the rod body on the lower end side of the second interlocking rod (40).

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