Wheel loader

Abstract

To provide a wheel loader that can suppress interference between an angle detection device that detects a bending angle of a vehicle body and hoses, harnesses, and the like that are routed across front and rear frames.SOLUTION: A wheel loader comprises a front frame (1A), a rear frame (1B) flexibly connected to the front frame via a center pin (33), and an angle detection device (50) detecting a bending angle of the front frame relative to the rear frame. The angle detection device comprises an angle sensor (51) detecting the bending angle based on a rotational position of a shaft portion (51a), and a link mechanism (52) connected to the shaft portion and rotating the shaft portion. The angle sensor is fixed to one of the front frame and the rear frame. The link mechanism is connected to the other of the front frame and the rear frame so as to transmit changes in a relative position between the front frame and the rear frame to the shaft portion of the angle sensor.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a wheel loader. [Background technology]

[0002] As background art in this technical field, for example, Patent Document 1 describes a vehicle body deflection angle detection device, which is characterized in that in a vehicle body articulating vehicle in which the front frame of the rear body and the rear frame of the front body are connected flexibly by a deflection shaft, a detection pin is vertically installed on one of the front and rear frames and the other is pivotally supported via a spherical bearing so as to be able to swing relative to the other, a vehicle body deflection angle detection sensor is attached to a bracket that protrudes slidably from the other of the front and rear frames, and the rotation detection shaft of the vehicle body deflection angle detection sensor is fitted into a guide pin on the detection pin to connect them. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 63-085569 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology described in Patent Document 1, the vehicle body bending angle detection device (angle detection device) is located on the same center as the bending axis (center pin) on which the hoses and harnesses that are routed across the front and rear frames are located, so the vehicle body bending angle detection device compresses the space in which the hoses and harnesses are routed. Also, the hoses and harnesses that slide as the vehicle body bends interfere with the vehicle body bending angle detection device, and the vehicle body bending angle detection device may be damaged by the load.

[0005] Therefore, an object of the present invention is to provide a wheel loader that can reduce interference between an angle detection device that detects the bending angle of the vehicle body and hoses, harnesses, etc. that are routed across the front and rear frames. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one aspect of the present invention is a wheel loader including a front frame, a rear frame flexibly connected to the front frame via a center pin, and an angle detection device that detects the bending angle of the front frame relative to the rear frame, wherein the angle detection device comprises an angle sensor that detects the bending angle based on the rotational position of an axle, and a link mechanism that is connected to the axle and rotates the axle, and the angle sensor is fixed to one of the front frame and the rear frame, and the link mechanism is connected to the other of the front frame and the rear frame so as to transmit a change in the relative position between the front frame and the rear frame to the axle of the angle sensor. Effect of the Invention

[0007] The wheel loader according to the present invention can suppress interference between the angle detection device, which detects the bending angle of the vehicle body, and the hoses, harnesses, etc. routed across the front and rear frames. Problems, configurations, and effects other than those described above will become apparent from the description of the embodiments below. [Brief description of the drawings]

[0008] [Figure 1] 1 is an external side view showing one configuration example of a wheel loader according to an embodiment of the present invention. FIG. [Diagram 2] FIG. 4 is an enlarged side view showing a main portion of the center joint. [Diagram 3] FIG. 4 is a plan view showing a main part of the center joint. [Figure 4] FIG. 4 is a perspective view showing a main part of a center joint. [Diagram 5] FIG. 4 is a perspective view showing a main part of a center joint. [Figure 6] FIG. 4 is a perspective view showing a main part of a center joint. [Figure 7] FIG. 4 is a perspective view showing a main part of a center joint. [Figure 8] FIG. 4 is an enlarged perspective view showing a main part of the center joint. [Figure 9A] FIG. 13 is a diagram showing a state in which the front frame is bent to approximately the middle position in the right direction. [Figure 9B] FIG. 13 shows a state in which the previous frame is bent to the maximum position to the right. [Figure 9C] FIG. 13 is a diagram showing a state in which the front frame is bent to approximately the middle position in the left direction. [Figure 9D] FIG. 13 shows the state in which the previous frame is bent to the maximum position in the left direction. [Figure 10] FIG. 4 is an enlarged side view showing a main part of the center joint according to the first modification; [Figure 11] FIG. 4 is an enlarged perspective view showing a main part of a center joint according to Modification 1. [Figure 12] FIG. 11 is an enlarged side view showing a main part of a center joint according to Modification 2. [Figure 13] FIG. 11 is an enlarged side view showing a main part of a center joint according to Modification 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First, the overall configuration of a wheel loader 1 according to an embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is an external side view showing an example of the configuration of a wheel loader 1 according to an embodiment of the present invention.

[0010] The wheel loader 1 is an articulated work vehicle that is steered by bending the vehicle body near the center, and a front frame 1A forming the front part of the vehicle body and a rear frame 1B forming the rear part of the vehicle body are connected by a center joint 30 so as to be rotatable in the left-right direction, and the front frame 1A bends in the left-right direction relative to the rear frame 1B. In the following explanation, of the left-right direction of the vehicle body, the left direction in the forward direction is referred to as the "left direction", and the right direction in the forward direction is referred to as the "right direction" (see Figure 3).

[0011] The vehicle body is provided with four wheels 11, two of which are front wheels 11A provided on both the left and right sides of the front frame 1A, and the remaining two wheels 11 are rear wheels 11B provided on both the left and right sides of the rear frame 1B. Of the four wheels 11, only the front wheel 11A and rear wheel 11B provided on the left side are shown in FIG.

[0012] A hydraulically driven working device 2 is attached to the front of the front frame 1A for carrying out loading and unloading work such as digging up work objects such as soil and minerals and loading them into a loading destination such as a dump truck or a hopper.

[0013] The rear frame 1B is provided with a cab 12 in which an operator sits, a machine room 13 that houses various devices required for driving the wheel loader 1, and a counterweight 14 for maintaining balance with the working implement 2 so that the vehicle body does not tilt. In the rear frame 1B, the cab 12 is disposed at the front, the counterweight 14 at the rear, and the machine room 13 between the cab 12 and the counterweight 14. A controller 70 is disposed in the cab 12, and an angle sensor 51, which will be described later, is connected to the controller 70 via electrical wiring on the same rear frame 1B. Detection information from the angle sensor 51 is input to the controller 70.

[0014] The working device 2 has a lift arm 21 attached to the front frame 1A so as to be rotatable in the vertical direction, two lift arm cylinders (not shown) as hydraulic cylinders that drive the lift arm 21, a bucket 23 attached to the tip of the lift arm 21 so as to be rotatable in the vertical direction, a bucket cylinder 24 as a hydraulic cylinder that drives the bucket 23, and a bell crank 25 rotatably connected to the lift arm 21 to form a link mechanism between the bucket 23 and the bucket cylinder 24.

[0015] The lift arm 21 rotates upward relative to the front frame 1A when the rods of the two lift arm cylinders extend, and rotates downward relative to the front frame 1A when the rods of the two lift arm cylinders contract.

[0016] The bucket 23 rotates upward relative to the lift arm 21 and tilts backward toward the front frame 1A (vehicle body) (tilt operation) as the rod of the bucket cylinder 24 extends, and rotates downward relative to the lift arm 21 and tilts forward (dump operation) as the rod of the bucket cylinder 24 contracts. This allows the bucket 23 to scoop up and discharge (discharge) work objects such as soil and minerals.

[0017] The bucket 23 can be replaced with various attachments, such as a blade, and the wheel loader 1 can perform various tasks such as snow removal and earth-pulling in addition to loading and unloading operations using the bucket 23.

[0018] This wheel loader 1 can be operated manually by an operator in the cab 12, or it can be operated remotely by an operator located away from the wheel loader 1 (autonomous running without an operator in the cab 12).

[0019] Next, details of the main parts including the center joint 30 will be described. Fig. 2 is an enlarged side view of the main parts of the center joint 30, Fig. 3 is a plan view of the main parts of the center joint 30, Figs. 4 to 7 are perspective views of the main parts of the center joint 30, and Fig. 8 is an enlarged perspective view of the main parts of the center joint 30. Note that the upper rear plate 32a constituting the rear joint portion 32 is omitted in Figs. 3, 5, and 7. Also, hoses and wiring 40 are shown only in Figs. 6 and 7.

[0020] 2 to 7, the center joint 30 has a front joint part 31, a rear joint part 32, and a center pin 33. Although only one set of the front joint part 31, the rear joint part 32, and the center pin 33 is shown in Fig. 2, in reality, two are provided spaced apart vertically. That is, the center joint 30 has a pair of upper and lower front joint parts 31, a pair of upper and lower rear joint parts 32, and a pair of upper and lower center pins 33.

[0021] The front joint portion 31 has a front plate 31a. The front plate 31a is fixed integrally to the front frame 1A and is provided so as to protrude horizontally from the rear of the front frame 1A toward the rear frame 1B.

[0022] The rear joint portion 32 has a pair of rear plates 32a, 32b and a partition wall 32c. The upper rear plate 32a is disposed above the front plate 31a, and the lower rear plate 32b is disposed below the front plate 31a. The upper rear plate 32a and the lower rear plate 32b are fixed integrally to the rear frame 1B and are provided so as to protrude horizontally from the front of the rear frame 1B toward the front frame 1A. The partition wall 32c is formed of a horizontally long plate body provided along the vertical direction between the upper rear plate 32a and the lower rear plate 32b (see FIG. 5). A horizontally long opening 32d is provided in the center of the partition wall 32c. A link mechanism 52, which will be described later, is inserted into the opening 32d.

[0023] The center pin 33 is disposed along the up-down direction (vertical direction) and connects the pair of rear plates 32a, 32b and the front plate 31a disposed therebetween so that they can rotate with each other.

[0024] The angle detection device 50 detects the bending angle of the front frame 1A with respect to the rear frame 1B, and includes an angle sensor 51 and a link mechanism 52 (see FIG. 8). The angle sensor 51 is fixed to the upper surface of the lower rear plate 32b at a position near the rear of the partition wall 32c (see FIG. 5).

[0025] As shown in FIG. 8, the link mechanism 52 is a mechanism for connecting the front plate 31a and the angle sensor 51, and includes a first arm 53 and a second arm 54. One end 53a of the first arm 53 is fixed to the shaft portion 51a of the angle sensor 51. Specifically, the shaft portion 51a is inserted into an insertion hole 53c provided in one end 53a of the first arm 53, and is fixed to the one end 53a by a screw 57. As a result, the shaft portion 51a rotates integrally with the first arm 53. Meanwhile, the other end 53b of the first arm 53 is rotatably connected to one end 54a of the second arm 54 via a first pin 55. The other end 54b of the second arm 54 is clamped by a pair of brackets 31b provided on the upper and lower sides of the front plate 31a, and is rotatably connected via a second pin 56.

[0026] Therefore, when the front frame 1A bends with respect to the rear frame 1B and the relative position between the front frame 1A and the rear frame 1B changes, the link mechanism 52 is displaced. Then, the shaft portion 51a of the angle sensor 51 rotates in accordance with the displacement of the link mechanism 52. The angle sensor 51 detects the rotation angle of the shaft portion 51a, thereby being able to detect the bending angle of the front frame 1A with respect to the rear frame 1B.

[0027] Next, the operation of the angle detection device 50 (particularly the link mechanism 52) when the vehicle body of the wheel loader 1 is bent will be described. Fig. 9A to Fig. 9D are diagrams showing a state in which the front frame 1A is bent in the left-right direction relative to the rear frame 1B. Specifically, Fig. 9A shows a state in which the front frame 1A is bent to an approximately intermediate position in the right direction, and Fig. 9B shows a state in which the front frame 1A is bent to a maximum position in the right direction. Fig. 9C shows a state in which the front frame 1A is bent to an approximately intermediate position in the left direction, and Fig. 9D shows a state in which the front frame 1A is bent to a maximum position in the left direction. However, in Figs. 9A to 9D, the illustration of the upper rear plate 32a is omitted. Note that the state in which the front frame 1A is not bent relative to the rear frame 1B, that is, the state in which the wheel loader 1 moves straight ahead, is as shown in Fig. 3.

[0028] 9A and 9B, when the front frame 1A is bent to the right, the link mechanism 52 is gradually displaced. Then, as shown in the figures, the shaft portion 51a of the angle sensor 51 rotates in the clockwise direction CW in a plan view.

[0029] 9C and 9D, when the front frame 1A is bent to the left, the link mechanism 52 is gradually displaced. Then, as shown in the figures, the shaft portion 51a of the angle sensor 51 rotates counterclockwise CCW in a plan view.

[0030] In this way, when the front frame 1A is bent in the left-right direction relative to the rear frame 1B, the shaft 51a of the angle sensor 51 rotates in a predetermined direction accordingly. The angle sensor 51 detects the rotation position of the shaft 51a, thereby detecting the bending angle of the front frame 1A relative to the rear frame 1B.

[0031] Next, the effects of the wheel loader 1 according to this embodiment will be described.

[0032] When the front frame 1A bends left or right with respect to the rear frame 1B and the relative positions of the two change, the angle sensor 51 detects the bending angle between them via the link mechanism 52. Therefore, the angle sensor 51 can be provided at a position away from the center pin 33 by a distance equivalent to the length of the link mechanism 52. As a result, even if soil, rocks, etc. are scattered onto the center pin 33 during excavation work by the wheel loader 1, the risk of the angle sensor 51 being damaged by the soil, etc. colliding with it is reduced because the angle sensor 51 is positioned away from the center pin 33.

[0033] In particular, according to this embodiment, since the partition wall 32c is provided in front of the angle sensor 51, scattering of soil and sand can be further prevented by the partition wall 32c. Therefore, the effect of preventing damage to the angle sensor 51 can be improved, and the life of the angle sensor 51 can be extended.

[0034] 6 and 7, many hoses and wirings 40 are routed around (especially above) the center joint 30. In the conventional technology described in Patent Document 1, an angle detection device is provided coaxially above the center pin 33, so that the angle detection device gets in the way of routing the hoses and wirings 40 across the front and rear frames 1A and 1B. In contrast, in this embodiment, the angle sensor 51 and the link mechanism 52 are accommodated between the upper rear plate 32a and the lower rear plate 32b of the rear frame 1B, so that the angle detection device 50 does not get in the way of routing the hoses and wirings 40. In other words, the angle detection device 50 does not take up space for routing the hoses and wirings 40. This increases the degree of freedom in routing the hoses and wirings 40.

[0035] It is also possible to suppress deterioration in workability when installing the hose / wiring 40 and the angle sensor 51. In addition, since interference between the hose / wiring 40 and the angle sensor 51 is avoided, the angle sensor 51 and the hose / wiring 40 are not subjected to unnecessary load, and damage to these components can be prevented.

[0036] In addition, since the angle sensor 51 and the controller 70 are provided on the same rear frame 1B, the wiring between them does not need to span the front and rear frames 1A, 1B. This prevents the wiring from being exposed, and reduces the risk of damage to the harness.

[0037] In addition, since the link mechanism 52 is configured to be displaceable within the range of the width of the opening 32d of the partition wall 32c, the link mechanism 52 does not interfere with bending of the vehicle body. In this way, according to this embodiment, it is possible to achieve both miniaturization of the angle detection device 50 and prevention of damage.

[0038] Next, various modifications of this embodiment will be described.

[0039] (Variation 1) Fig. 10 is an enlarged side view of a main part of the center joint 30-1 according to the first modification, and Fig. 11 is an enlarged perspective view of a main part of the center joint 30-1 according to the first modification. As shown in Figs. 10 and 11, in the first modification, the angle detection device 50 is placed on the lower surface of the upper rear plate 32a. Even with this configuration, the same effects as those of the present embodiment described above can be achieved.

[0040] (Variation 2) Fig. 12 is an enlarged side view showing a main part of the center joint 30-2 according to the second modification. As shown in Fig. 12, in the second modification, the angle detection device 50 is placed on the upper surface of the front plate 31a. Therefore, the other end of the link mechanism 52 is rotatably connected to the bracket 32e provided on the upper surface of the upper rear plate 32a. Even with this configuration, the same effects as those of the above-mentioned embodiment can be obtained. Moreover, according to this configuration, the angle detection device 50 is easily accessible, and therefore, the maintenance is easy.

[0041] (Variation 3) FIG. 13 is an enlarged side view showing a main part of the center joint 30-3 according to the third modification. As shown in FIG. 13, in the third modification, the angle detection device 50 is placed on the lower surface of the front plate 31a. Therefore, the other end of the link mechanism 52 is rotatably connected to the bracket 32e provided on the lower surface of the lower rear plate 32b. Even with this configuration, the same effects as those of the above-mentioned embodiment can be obtained. Moreover, according to this configuration, since the angle detection device 50 is placed on the lower surface of the front plate 31a, the angle detection device 50 does not get in the way of the hoses and wiring 40 arranged above the center pin 33.

[0042] It should be noted that the above-described embodiments are merely illustrative examples of the present invention, and are not intended to limit the scope of the present invention to these embodiments. Those skilled in the art can implement the present invention in various other forms without departing from the gist of the present invention. [Explanation of symbols]

[0043] 1. Wheel loader 1A Front frame 1B Rear frame 2. Working Equipment 11 wheels 12 Cab 13 Machine room 14 Counterweight 21 Lift arm 23 Bucket 24 Bucket Cylinder 25 Bell crank 30 Center joint 31 Front joint 31a Front plate 31b Bracket 32 Rear joint 32a Upper rear plate 32b Lower rear plate 32c bulkhead 32d aperture 32e Bracket 33 Center pin 40 Hoses and wiring 50 Angle detection device 51 Angle Sensor 51a Shaft 52 Link mechanism 53 First Arm 53a one end 53b Other end 53c Insertion hole 54 Second Arm 54a one end 54b other end 55 1st pin 56 2nd pin 57 Screw 70 Controller

Claims

1. A wheel loader including a front frame, a rear frame flexibly connected to the front frame via a center pin, and an angle detection device that detects a bending angle of the front frame relative to the rear frame, The angle detection device is an angle sensor that detects the bending angle based on a rotation position of the shaft portion; a link mechanism connected to the shaft portion and rotating the shaft portion; the angle sensor is fixed to one of the front frame and the rear frame, the link mechanism is connected to the other of the front frame and the rear frame so as to transmit a change in the relative position between the front frame and the rear frame to the shaft portion of the angle sensor; A wheel loader characterized by the above.

2. The wheel loader according to claim 1, a controller connected to the angle sensor and receiving information on the refraction angle detected by the angle sensor; the angle sensor and the controller are mounted on the rear frame, The other end of the link mechanism is attached to the front frame. A wheel loader characterized by the above.

3. The wheel loader according to claim 2, The link mechanism includes a first arm member and a second arm member. one end of the first arm member is fixed to the shaft portion of the angle sensor, and the other end is rotatably connected to one end of the second arm member via a first pin; The other end of the second arm member is rotatably connected to a side portion of the front frame via a second pin. A wheel loader characterized by the above.

4. The wheel loader according to claim 2, The rear frame has a pair of upper and lower rear plates at a tip end thereof, the upper and lower rear plates extending horizontally from the rear frame toward the front frame, The angle sensor is disposed between the pair of upper and lower rear plates. A wheel loader characterized by the above.

5. The wheel loader according to claim 4, the rear frame has a partition wall provided along a vertical direction between the pair of upper and lower rear plates, The angle sensor is disposed near the rear of the partition wall, The partition wall has an opening extending in a vehicle width direction, The link mechanism is disposed by being inserted through the opening. A wheel loader characterized by the above.

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