JPH0526582U - Wheel loader gear shift operation device - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] A gear shift operation device of a four-wheel-drive wheel loader that has a work machine such as an excavator in the front part of a vehicle body (EN) Provided is a gear shift operation device for a wheel loader, which is easy to operate. [Structure] A gear shift lever 11, a handle 12, an accelerator pedal 14, a brake pedal 15, and a working machine lever 13 for operating a working machine are provided, and a grip portion 13a of the working machine lever 13 is provided with a downshift switch. 16 and the grip portion 13a are provided with a shift-up switch 17 for shifting from a lower speed to a higher forward vehicle speed, or with a shift-up switch beside the brake pedal 15 so that when the tire slips, By using the work implement lever 13 or the shift up switch 16 beside the brake pedal 15 which is operated without releasing the hand, the shift force is changed from low speed to high speed to reduce the thrust force and the slip is eliminated.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gear shift operating device for a four-wheel-driven wheel loader, which has a work machine such as a shovel in a front part of a vehicle body.

[0002]

[Prior Art]

 As shown in FIG. 6, the wheel loader has a work machine 2 such as an excavator that can be rocked and raised and lowered at the front part of a vehicle body 1. The vehicle body 1 can be freely run by four-wheel tires 3. Is becoming Then, while moving the vehicle body 1 forward, the earth and sand 4 and the like are scooped onto the working machine 2, and while moving the vehicle body 1 backward, the earth and sand 4 inside the working machine 2 are discharged to, for example, a truck bed. In order to perform these operations, the vehicle body 1 of the wheel loader has a gear shift lever 11 for switching the forward or reverse vehicle speed among a plurality of gears, a handle 12 for turning the vehicle body, and a work machine lever for operating the work machine. A gear shift operation device including 13 and the like is provided.

In such a wheel loader, especially when the vehicle body 1 is advanced toward the earth and sand 4, the vehicle is operated at a high speed of two speeds immediately before the plunge, but in order to obtain a large plunging force immediately before the plunge. , Change the vehicle speed from high speed second speed to low speed first speed. At the same time, it is necessary to operate the work implement lever to operate the work implement 2. Since the handle is held with one hand and the work implement lever is held with one hand, in order to operate the gear shift lever, the hand must be released from the handle to operate the gear shift lever. It was complicated and required skill.

Therefore, conventionally, in order to simplify the operation of the wheel loader when thrusting, there has been proposed a gear shift operating device in which a gear shift lever is provided with a shift down switch (Japanese Utility Model Laid-Open No. 59-107663 and Japanese Laid-Open Patent Publication No. Sho. 63-275432). A gear shift operating device provided with this shift down switch will be described with reference to FIG.

In FIG. 5, reference numeral 11 denotes a speed change lever laterally attached to the handle post. When the speed change lever is oscillated, it switches between forward and reverse, and when rotated, it switches between high speed second speed and low speed first speed. The speed change lever 11 switches the hydraulic clutch 22 via the control device 20 and the electromagnetic valve device 21. The hydraulic clutch 22 is provided between the four wheels 23 and the torque converter 24, and the torque converter 24 is driven by the engine 25. The main pump 26 is connected to the engine 25 via gears. Reference numeral 12 denotes a steering wheel, which turns the vehicle body in a predetermined direction through the four wheels 23. A working machine lever 13 operates a working machine 27 driven by hydraulic pressure from the main pump 26. Reference numeral 14 denotes an accelerator pedal, which controls the rotation speed of the engine 25. A brake pedal 15 brakes the four wheels 23. Reference numeral 16 denotes a downshift switch provided on the grip portion 13a of the operating device lever 13, which switches the vehicle speed from the second speed to the first speed via the control device 20 and the electromagnetic valve device 21.

In the above-described speed change operation device, the speed change lever 11 is set to the second forward speed in advance, and the handle 12 is held by one hand and the work implement lever 13 is held by one hand, and the earth and sand are held. The thrust force is obtained by pushing the shift-down switch 16 provided on the grip portion 13a of the operating lever 13 immediately before the push-in operation. Therefore, shifting can be performed without releasing the hand from the handle 12, and it is easy to perform variable speed tamping, and the operation becomes easy.

[0007]

[Problems to be solved by the device]

 However, when the shift down switch 16 is pressed to switch the vehicle speed from the second speed to the first speed, the thrust force against the sand and sand increases, but on the other hand, the four wheel tires may slip due to the ground condition during the thrust. Therefore, when tire slip occurs, the accelerator pedal 14 is loosened, the output of the engine 25 is reduced, and the thrust force is weakened to prevent slipping. However, when the output of the engine 25 is reduced, the cargo handling performance of the working machine 27 is also reduced, which causes a problem in excavation work.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to improve the thrust force without degrading the cargo handling performance of the working machine when the tire slips. Another object of the present invention is to provide a gear shift operating device for a wheel loader that can be easily dropped and prevented from slipping.

[0009]

[Means for Solving the Problems]

 The gear shift operation device for a wheel loader of the present invention comprises a gear shift lever for switching the vehicle speed, a handle for turning the vehicle body, an accelerator pedal, a brake pedal, and a work machine lever for operating the work machine. In a gear shift operating device for a wheel loader, wherein a grip down portion of the work implement lever is provided with a shift-down switch for shifting from a high speed to a low forward vehicle speed. It is provided with a shift-up switch for shifting gears. In addition, instead of the shift-up switch on the work equipment lever, there is also a shift-up switch provided beside the brake pedal.

[0010]

[Action]

 When a tire slips, the work equipment lever or shift-up switch beside the brake pedal, which can be operated without releasing the handle, shifts from low speed to high speed to reduce the plunge force and eliminate the slip.

[0011]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a gear shift operating device of a wheel loader of the present invention. In addition, about the part which operates similarly to what was demonstrated in FIG. 5, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

1 is different from FIG. 5 in that a shift-up switch 17 provided on the grip portion 13a of the operating device lever 13 is provided, and a hydraulic clutch 22 is provided via a control device 20 and a solenoid valve device 21. The point is that the speed is switched from low speed to high speed. While holding the handle 12 with one hand and the work implement lever 13 with one hand, just before plunging into the soil, the shift down switch 16 switches from high speed to low speed to obtain a large plunging force. If the tire slips on the ground, the pushing force will drop and the tire will wear. Therefore, hold the handle 12 with one hand and the work machine lever 13 with one hand, The shift-up switch 17 switches from low speed to high speed to reduce the plunge force and eliminate slip. At this time, the accelerator pedal 14 can be left as it is, and the discharge pressure of the main pump 26 with respect to the working machine 27 will not be reduced.

FIG. 2 is a sectional view of the grip portion of the operating lever. A cavity 16b covered with a rubber 16a is provided at the top of the grip portion 13a, and the shift down switch 16 is embedded in the cavity 16b. A cavity 17b covered with a rubber 17a is provided on a side surface of the grip portion 13a and slightly below the shift portion 17a, and a shift-up switch 17 is embedded in the cavity 17b. With the grip of the operating lever held by the right hand, the shift down switch 16 can be operated by the thumb and the shift up switch 17 can be operated by the middle finger.

FIG. 3 is a circuit diagram of the control device 20 for operating the solenoid valve device 21 by the shift down switch 16 and the shift up switch 17. RY1 to RY4 are relays, and A to G and I to K are terminals. The shift-up switch 17 is connected between the A and B terminals, the shift-down switch 16 is connected between the E and F terminals, the C terminal is the first speed of the shift lever, the D terminal is the second speed of the shift lever, The G terminal is connected to the forward movement of the shift lever. On the other hand, the J terminal is connected to the first speed switching solenoid F1 of the solenoid valve device, the K terminal is connected to the second speed switching solenoid F2 of the solenoid valve device, and the I terminal is the earth. During the operation in the second forward speed, the current flows from the D terminal through the relay RY1 through the diode to the second terminal switching solenoid F2 at the K terminal, and the relay RY3 is in the operating state. In this state, when the downshift switch 16 is pressed to connect the terminals E and F, the relays RY2 and RY1 are activated, the circuit to the second speed switching solenoid F2 is cut off, and the current from the D terminal is relayed by the relay RY1. Through the first speed switching solenoid F 1 and downshifted to the first speed. When the tire starts slipping during the excavation work in this state, the shift-up switch 17 is pressed to connect the terminals A and B to operate the relay RY4. When the relay RY4 operates, the circuits of the relays RY2 and RY1 are cut off, the operations of the relays RY2 and RY1 stop, and the current from the D terminal passes through the relay RY1 and passes through the diode to switch between the two-speed switching of the terminal K. It flows to the solenoid for use F2 and is upshifted to the second speed. Here, when the shift down switch 16 is further pushed, the relays RY2 and RY1 are operated, the current flows to the first speed switching solenoid F1 of the terminal J, and the first speed is downshifted.

FIG. 4 is a diagram showing another embodiment of the shift-up switch. The grip portion 13a of the operation lever 13 is only the conventional shift down switch 16, and the shift down switch 18 is provided on the left side of the brake pedal 15. During the thrusting work, the right foot is operating the accelerator pedal 14, but the left foot is on the brake pedal 15 and is in a play state. Therefore, when a slip occurs, the shift down switch 18 on the left side of the brake pedal 15 is pushed to shift up. As shown in FIG. 2, there is no risk of erroneous operation due to the close proximity of the switches 16 and 17, and it is possible to shift down without releasing the handle 12.

[0016]

[Effect of the device]

 The shift operation device of the wheel loader of the present invention shifts from low speed to high speed and pushes in when a slip occurs in the tire by a work machine lever or a shift up switch beside the brake pedal which is operated without releasing the handle. Since the slip is eliminated by reducing the force, it is possible to prevent the wear of the tire due to the slip at the time of plunging. In addition, since it is not necessary to loosen the accelerator pedal, it is possible to prevent the slip by reducing the plunging force without degrading the cargo handling performance of the working machine. In addition, the shift-up switch can be operated conveniently without taking your hands off the handle.

[Brief description of drawings]

FIG. 1 is a view showing a gear shift operating device of a wheel loader of the present invention.

FIG. 2 is a cross-sectional view of a grip portion of an operating device lever.

FIG. 3 is a circuit diagram of a control device for operating the solenoid valve device by a shift down switch and a shift up switch.

FIG. 4 is a diagram showing another embodiment of the shift-up switch.

FIG. 5 is a diagram showing a conventional gear shift operating device of a wheel loader.

FIG. 6 is an external view of a wheel loader.

[Explanation of symbols]

 11 Gearshift lever 12 Handle 13 Work implement lever 14 Accelerator pedal 15 Brake pedal 16 Shift down switch 17, 18 Shift up switch

Claims (2)

[Scope of utility model registration request] 1. A gear shift lever for switching a vehicle speed, a steering wheel for turning a vehicle body, an accelerator pedal, a brake pedal, and a work implement lever for operating a work implement. The work implement lever is gripped. In a gear shift operating device of a wheel loader, which has a shift down switch for shifting from a high speed to a low forward vehicle speed, a shift up switch for shifting from a lower speed to a higher forward vehicle speed is provided in the grip portion of the working machine lever. A gear shift operation device for a wheel loader, which is provided. 2. The shift operating device for a wheel loader according to claim 1, wherein a shift up switch is provided beside the brake pedal instead of the shift up switch of the work implement lever. Operating device.