JPH03248929A - Inching control device for industry vehicle - Google Patents

Abstract

PURPOSE:To make a brake and a clutch concurrently controllable with the single operation of a brake pedal by directly interlocking the brake pedal and a clutch adjusting means with an inching interlocking mechanism. CONSTITUTION:The pushing down of a brake pedal 1 causes a rotary tube 5 inlaid in a supporting axis 4 to rotate via a lever 6, etc. Also concurrently an inching valve 24 operates via another lever 8 and an inching cable 22 to gradually move the connection condition of an unshown clutch to a disconnection side. Moreover a master cylinder 12 commences its operation via another lever 7, etc., concurrent with the complete disconnection of the clutch to gradually increase the braking force of a brake with the pushing down of the brake pedal 1. This causes the braking force of the brake and the connected quantity of the clutch to be together adjusted respectively with the single operation of the brake pedal 1 to improve operability.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an inching control device for an industrial vehicle, and more specifically, the braking force and clutch engagement amount are mechanically adjusted in conjunction with each other to bring the vehicle to a slight speed. This invention relates to an inching control device for driving or driving.

[Conventional technology]

In general, industrial vehicles may be required to have different driving performance than normal automobiles.For example, in a vehicle that performs cargo handling work such as a forklift truck equipped with a torque converter, it is necessary to hold the cargo or carry out the cargo handling in a specified manner. In order to place the vehicle at a specific location, it is required to run at very low speed or drive. Therefore, in order to obtain such special driving performance, forklifts, etc. are equipped with a so-called inching function, which adjusts the amount of clutch engagement to limit the vehicle's driving force, and at the same time applies braking using the brakes. ing. For example, when holding a cargo, the vehicle is driven or driven at a slow speed by applying braking in the half-clutch state, as described above, so that the vehicle can gradually approach the cargo and hold it accurately.

An example of an industrial vehicle having the above-mentioned inching function is the vehicle described in Japanese Utility Model Publication No. 63-29616. This industrial vehicle is equipped with a normal brake pedal 31 and an inching pedal 32, and when the brake pedal 31 is operated, a mask cylinder 33 is operated as usual, and braking is performed by the brake. Furthermore, when the inching pedal 32 is operated, the inching valve 35 is activated via the link mechanism 34.
is operated to adjust the amount of clutch engagement, and
The mask cylinder 33 is actuated via the interlocking mechanism 36, and braking is performed by the brake. That is, the inching operation is performed using a dedicated inching pedal 32.

However, in order to perform an inching operation in the above-mentioned vehicle, it is necessary to switch the foot from the accelerator or brake pedal 31 to the inching pedal 32, which makes it impossible to perform a speedy operation.

Therefore, there are some industrial vehicles in which the brake pedal has the function of an inching pedal, such as the industrial vehicle described in Japanese Patent Publication No. 56-37094. To explain this vehicle, the forward/reverse switching valve 38 operates depending on the operating direction of the forward/reverse lever 37, and hydraulic oil from the hydraulic pump 39 is supplied to the forward and reverse clutches 40a.

40b so that the vehicle moves forward or backward. Further, when the brake pedal 41 is operated, the brake 42 is operated, and the hydraulic oil is introduced into the cylinder 43 to move the piston 43a to the right. As a result, the lever 44 tilts to move the inching valve 45 to the left, allowing the hydraulic fluid from the hydraulic pump 39 to escape. Since the amount of hydraulic oil supplied is limited, the clutches 40a and 40b are in a half-clutch state. Therefore, inching can be performed by operating the brake pedal 41.

[Problem to be solved by the invention]

However, in the latter industrial vehicle, the inching valve 45 is indirectly operated by using the hydraulic pressure of brake hydraulic fluid.
is being moved. Therefore, when the temperature of the brake hydraulic oil rises and expands due to brake heat generated by braking, the piston 43a moves to the right even though the amount of operation of the brake pedal 41 does not change, and the clutches 40a, 40
The connection state of 0b may be changed. Conversely, when the temperature of the clutch hydraulic oil increases, the piston 43a moves to the left, changing the operating state of the brake 42. Therefore, in this vehicle, the brake 42
There is also a problem that the inching operation amount is unstable and the operation feeling is poor.

Also, the braking force of the brake 42 and the clutch 40a.

It is necessary to adjust the connection amount of 40b according to the amount of pedal operation, but in the above-mentioned industrial vehicles, the hydraulic circuit is complex and there are many adjustment elements, so it is difficult to adjust to the desired braking force and connection amount. there were.

An object of the present invention is to provide an industrial vehicle in which an inching operation can be performed quickly using an existing brake pedal without replacing the foot on the pedal, a good feeling of operation of the brake and inching, and easy adjustment of the operation amount. An object of the present invention is to provide an inching control device.

[Means to solve the problem]

The present invention provides an industrial vehicle comprising a brake drive means for operating a brake for braking a vehicle, and a brake pedal for operating the brake drive means, including a clutch adjustment means for adjusting the amount of clutch engagement of the vehicle, and a brake pedal for operating the brake drive means. The gist of the present invention is an inching control device for an industrial vehicle equipped with an inching interlocking mechanism that mechanically directly interlocks a pedal and a clutch adjusting means.

[Effect]

When the brake pedal is operated, the brake is actuated by the brake driving means, and the vehicle is braked.

At the same time, the clutch adjusting means is operated via the inching interlocking mechanism, and the amount of clutch engagement is adjusted.

As a result, the running speed of the vehicle is limited and inching is performed, allowing slow running and driving.

Since the inching operation can be performed using the brake pedal in this way, there is no need to replace the foot on the pedal.

Further, the brake driving means is directly operated by the brake pedal, and similarly, the clutch adjusting means is also directly operated by the brake pedal via an inching interlocking mechanism. Therefore, the brake drive means and the clutch adjustment means are prevented from influencing each other.

Further, since the clutch adjusting means is mechanically linked to the brake pedal by an inching interlocking mechanism, the operation timing of the clutch adjusting means can be easily changed by adjusting the inching interlocking mechanism.

〔Example〕

Hereinafter, a first embodiment will be described in which the present invention is embodied in an inching control device for a forklift equipped with a torque converter.
This will be explained according to Figures 7 to 7.

FIG. 1 is a perspective view of the inching control device of this embodiment and a brake pedal of a forklift, and FIG.
3 is a sectional view taken along the YY line in FIG. 1, and FIG. 4 is a sectional view taken along the Z-Z line in FIG. 1. The inching control device shown in these figures is installed together with a brake pedal 1 in the driver's seat of a forklift. The base end of the brake pedal 1 is rotatably supported around a shaft 2, and the brake pedal 1 is rotated counterclockwise (in the direction of arrow A in FIG. 1) by a torsion spring 3 wound around the shaft 2. It is biased and always held in a fixed position by a stopper (not shown).

As shown in FIGS. 1 and 2, a support shaft 4 is fixed above the brake pedal 1 by a fixing member (not shown), and a rotary cylinder 5 is rotatably fitted into the support shaft 4. Three levers 6 to 8 are integrally molded on the outer peripheral surface of the rotary cylinder 5, and the lever 6 on the right side is connected to the base end of the brake pedal l via a connecting plate 9 with a connecting pin 10.1.
They are connected by 1. Then, when the brake pedal 1 is depressed against the biasing force of the torsion spring 3, the brake pedal 1
rotates clockwise (in the direction of arrow B), and at the same time, the rotary cylinder 5 also rotates clockwise (in the direction of arrow C). As shown in FIGS. It is connected to the piston rod 13 of the brake mask cylinder 12 by a connecting pin 14, and this mask cylinder 12
is connected to a brake (not shown) of the forklift via a pipe 15. When the brake pedal 1 is depressed as described above, the piston rod 13 is pushed as the rotary cylinder 5 rotates, and the hydraulic oil in the mask cylinder 12 is supplied to the brake via the pipe 15. Since the supply of hydraulic oil at this time is set to start in the latter half of the pedal stroke, the braking force of the brake is generated in the latter half of the pedal stroke, as shown in FIG.

Further, as shown in FIGS. 1 and 4, a swinging lever 16 is rotatably supported by a shaft 17 below the left lever 8, and one end of this swinging lever 16 and the lever 8 are connected. pin 1
8.19 through a rod 20. The other end of the swing lever 16 is connected to one end of an inching cable 22 by a connecting pin 21, and the other end of the cable 22 is used as a clutch adjusting means for adjusting the amount of engagement of a wet clutch mounted on a forklift. It is connected to the inching valve 24. For example, the inching valve 24 may include a hydraulic pump 39 to a clutch 40a, as in the conventional example shown in FIG.

A valve 45 configured to vent hydraulic fluid supplied to 40b can be used.

In this embodiment, the above-described swing lever 16, shaft 17,
The connecting pins 18, 19, 21, the rod 20, and the inching cable 22 constitute an inching interlocking mechanism.

When the brake pedal 1 is depressed as described above, the swing lever 16 rotates via the rod 20 as the rotary cylinder 5 rotates, the inching cable 22 is pulled, and the inching valve 24 is activated. At this time, the inching valve 24 starts operating immediately after the start of depression of the brake pedal 1, and the clutch is completely disengaged in the middle of the pedal stroke. Therefore, as shown in FIG. 5, the clutch engagement state is adjusted during the first half of the pedal stroke.

Also, the total length of the inching cable 22 is the same as the nut 2.
For example, by adjusting the amount of rotation of the nut 0 23 during initial adjustment of the forklift, the actuation timing of the inching valve 24 relative to the amount of depression of the brake pedal 1 can be changed. ing.

Next, the operating status of the inching control device for a forklift constructed as described above will be explained.

During normal driving, brake pedal 1 is not depressed,
As shown on the left side of FIG. 5, no braking force is generated and the clutch is in the fully engaged position.

When the brake pedal 1 is started to be depressed from the above-mentioned state, the inching valve 24 is operated via the inching cable 22 as the rotary cylinder 5 rotates, and the clutch connection state gradually shifts to the new regulation.

Then, the clutch becomes completely disengaged in the middle of the pedal stroke, and thereafter remains in the disengaged state even if the pedal stroke increases.

Also, at the same time as the clutch is completely disengaged, the mask cylinder 1
2 starts operating, and the braking force of the brake gradually increases as the brake pedal 1 is depressed. When the brake pedal 1 is depressed the most, the braking force of the brake becomes maximum.

On the other hand, when the amount of depression of the brake pedal 1 is gradually decreased from the most depressed state, the amount of clutch engagement and the braking force of the brake follow the above-described process in reverse. That is, when the amount of depression begins to decrease, the braking force of the brake gradually decreases, and from the time the braking force disappears, the connected state of the clutch gradually shifts to the engaged side. Then, when the brake pedal 1 is no longer depressed again, the clutch is brought into the fully engaged position.

Therefore, the amount of engagement of the clutch and the braking force of the brake are adjusted according to the amount of depression of the brake pedal 1, and so-called inching is performed. For example, by maintaining the amount of depression of the brake pedal I at a predetermined amount, the amount of clutch engagement and the braking force of the brake are adjusted to a predetermined value, and the forklift can be driven at a slow speed, and furthermore, the amount of depression at that time can be varied as appropriate. can drive a forklift.

Note that during normal braking to decelerate or stop the forklift, there is play up to the middle of pedal stroke 1, and braking force is generated in the subsequent strokes.

In this way, the inching control device for a forklift according to the present embodiment allows the brake pedal 1 and the inching valve 24 to be linked, so that the inching operation can be performed using the brake pedal 1.

Therefore, when performing an inching operation, it is sufficient to simply press the brake pedal 1 with the foot placed on it, and since there is no need to replace the foot, a speedy operation can be performed.

Further, the mask cylinder 12 is directly operated by the brake pedal 1, and similarly, the inching valve 24 is also directly operated by the brake pedal 1 via each member 16-22 of the inching interlocking mechanism. Therefore, the brake and inching hydraulic circuits are completely independent of each other, and even if the temperature of the hydraulic oil rises and expands in either hydraulic circuit,
Does not affect the operation of the other circuit. Therefore, a good feeling of braking and inching operation can always be obtained.

3 Z Furthermore, inching valve 2 for brake pedal 1
4 is mechanically linked by an inching interlocking mechanism such as a swing lever 16 or an inch puffer cable 22. For example, by changing the amount of rotation of a nut 23 of the inching cable 22, the actuation timing of the inching valve 24 is adjusted. can do. Therefore, at the time of initial adjustment of the forklift, etc., a desired inching state according to the map shown in FIG. 5 can be easily achieved by adjusting the inching interlocking mechanism.

It should be noted that the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, as shown in FIG. 5, braking force is generated at the same time as the clutch is completely disengaged in the middle of the pedal stroke. However, as shown in Figure 6,
The braking force may be generated before the clutch is completely disengaged. With this setting, when the inching operation is performed while climbing, the brake will generate braking force before the clutch is completely disengaged and the driving force disappears, preventing the vehicle from moving backwards due to the slope. I can do it.

4 In addition, as mentioned above, the nut 2 of the inching cable 22
Such a setting is possible by changing the amount of rotation in step 3.

Further, as shown in FIG. 7, the rate of change between the clutch engagement amount and the braking pressure J may be made different. For example, the lever length on the mask cylinder 12 side and the inch puffer cable 22
This kind of setting is possible by making the lever lengths on the sides different.

Specifically, in the above embodiment, the inching control device for a forklift equipped with a torque converter is used, and the connection amount of the wet clutch is adjusted by the inching valve 24. The present invention may be embodied in an inching control device for a forklift, and the amount of connection of a dry single-plate clutch may be controlled by an actuator serving as a clutch adjustment means.

〔Effect of the invention〕

As described in detail above, according to the inching control device for an industrial vehicle of the present invention, it is possible to quickly perform an inching operation using an existing brake pedal without replacing the foot on the pedal, and it is also possible to perform brake and inching operations. It has excellent effects such as a good feeling and easy adjustment of the amount of operation.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an inching control device and a brake pedal of a forklift according to an embodiment, and FIG.
Figure 3 is a cross-sectional view along the YY line in Figure 1, Figure 4 is a cross-sectional view along the Z-X line in Figure 1, and Figure 5 shows the relationship between clutch engagement amount and braking force with respect to pedal stroke. Characteristic diagram, Figure 6 is a characteristic diagram of another example in which the braking force is generated before the clutch is completely disengaged, and Figure 7 is a characteristic diagram of another example in which the rate of change between the clutch engagement amount and the braking force is different. 8 is a perspective view showing a conventional inching device equipped with a dedicated pedal, and FIG. 9 is a hydraulic circuit diagram showing another conventional inching control device in which the inching operation is performed using a brake pedal. be. 1 is a brake pedal, 12 is a mask cylinder as a brake driving means, 16 is a swinging lever that constitutes an inching interlocking mechanism, 17 is a shaft that constitutes an inching interlocking mechanism, and 18, 19.21 are connections that constitute an inching interlocking mechanism. A pin, 20 a rod constituting an inching interlocking mechanism, and 22 an inching cable constituting an inching interlocking mechanism.

Claims (1)

[Scope of Claims] 1. Clutch adjustment means for adjusting the amount of clutch engagement of the vehicle in an industrial vehicle comprising: a brake drive means for operating a brake for braking the vehicle; and a brake pedal for operating the brake drive means. An inching control device for an industrial vehicle, comprising: and an inching interlocking mechanism that mechanically directly interlocks the brake pedal and the clutch adjustment means.