JP3018509B2 - Idle adjustment device for industrial vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idle adjusting device for an industrial vehicle, and more particularly to an idle adjusting device for an industrial vehicle such as a forklift.

[0002]

2. Description of the Related Art Generally, in an engine driven forklift or the like, a pump for supplying a control hydraulic pressure for cargo handling work is driven by an engine. For this reason, the idling adjustment device increases the engine speed at or above the engine speed required for vehicle running during cargo handling, thereby preventing a shortage of supplied hydraulic pressure.

[0003] As such an idle adjusting device, for example, one described in Japanese Patent Application Laid-Open No. 62-79200 is known, and is shown in FIG. In FIG.
An operation lever 2 for a cargo handling operation rotatably supported around the pin 1 is connected to a control valve 4 via a link 3. The control valve 4 controls hydraulic pressure supplied to a cylinder of the cargo handling device, and the hydraulic pressure is supplied by a pump (neither is shown) driven by an engine. The operation lever 2 is rotatably connected to the link 5, and the pin 6 a of the lever 6 is engaged with the long hole 5 a of the link 5. The lever 6 is fixed to a rotatable shaft 7, and the shaft 7 is fixed to a lever 8. The lever 8 is rotatably connected to a link 10 via a pin 9, and a pin 11 a of an accelerator arm 11 is engaged with a long hole 10 a of the link 10. The accelerator arm 11 is connected to an accelerator pedal 13 via a rod 12, and is also connected to an accelerator wire 14. The accelerator wire 14 is urged by a return spring (not shown) in a direction of decreasing the engine speed.

Here, the operating lever 2 is rotated around the pin 1 in FIG.
When turned clockwise or counterclockwise at,
In either case, the lever 6 rotates counterclockwise in FIG. 3 around the shaft 7, and the link 10 is pulled upward in FIG.
As a result, the accelerator pedal 13 is rotated counterclockwise in FIG. 3, and the engine speed increases via the accelerator wire 14. When the operation lever 2 is returned to the neutral position, the lever operation is not transmitted to the accelerator wire 14, but the accelerator wire is pressed by the return spring.
14 returns and the engine speed decreases. On the other hand, when the accelerator pedal 13 is depressed, the accelerator operation is transmitted to the accelerator wire 14, but is linked by the elongated hole 10.
Not transmitted to 10.

[0005] Therefore, when the cargo handling work is performed in a stopped state of the vehicle or in a state where the vehicle is repeatedly stopped and moved, only by operating the operation lever 2 for the cargo handling work, the cargo handling device is driven and the engine is automatically operated. Since the rotation speed increases, sufficient hydraulic pressure can be supplied to the cylinder of the working device. Further, after the work is completed, the rotation speed of the engine can be automatically reduced simply by returning the operation lever 2.

[0006]

However, in such a conventional idle adjusting device, the operation lever 2
The amount of rotation of the accelerator arm 11 due to the operation of the accelerator pedal is equal to the amount of rotation of the accelerator arm 11 due to the accelerator operation of the accelerator pedal 13, so that the amount of rotation of the accelerator arm 11 was sufficient to supply sufficient hydraulic pressure to the cargo handling device. In this case, there is a problem that the adjustment range of the engine speed by the accelerator pedal 13 becomes large, and it becomes difficult to drive the vehicle at low speed. Conversely, when the adjustment range of the engine speed by the accelerator pedal 13 is reduced, there is a problem that the hydraulic pressure supplied to the cargo handling device is insufficient. In addition, since a complicated link mechanism composed of many connecting members such as the links 5, 10 and the levers 6, 8 is provided in order to make it possible to adjust the number of revolutions of the engine during the loading operation,
There has been a problem that the device becomes larger and the structure becomes complicated.

It is an object of the present invention to reduce the size and simplification of the apparatus while enabling sufficient hydraulic pressure to be supplied during cargo handling work and to facilitate low-speed running during running.

[0008]

[Means for Solving the Problems]

According to a first aspect of the present invention, there is provided an engine speed changing means for changing an engine speed, which is connected to an accelerator pedal and driven in accordance with an accelerator operation amount of the accelerator pedal. One driving means;
A second drive unit connected to the engine speed change unit and capable of driving the engine speed change unit; a first drive unit and a second drive unit connected to each other to extend and contract the first drive unit and the second drive unit; A first connecting means, and a contact portion capable of contacting the first driving means. The driving of the first driving means in the direction of increasing the engine speed is restricted by the contact of the contacting part and the first driving means. A first restricting means, and a contact part which comes into contact with the first drive means when the accelerator pedal is not operated by the accelerator, and the first contact means and the first drive means contact the first drive means in the direction of decreasing the engine speed. The second restricting means for restricting the driving of the driving means, and the connecting means contracts or expands in a state where the contact between the first driving means and the contact part of the first restricting means is held by the accelerator operation of the accelerator pedal. And was controlled as When the second driving means is driven by the connecting means to increase the engine speed, and when the connecting means is controlled to contract or extend when the accelerator pedal is not operated by the accelerator, the driving of the first driving means is controlled by the second restriction. And drive control means controlled by the means to drive the second drive means to increase the engine speed by the connection means.

[0010]

[Action]

According to the first aspect of the present invention, the expansion and contraction of the connecting means is controlled by the control means, and the driving of the first driving means for increasing the engine speed by the contact of the contact portion of the first regulating means and the first driving means. Is controlled, and when the connecting means is controlled to contract or expand by the control means while maintaining the state in which the first driving means is in contact with the contact portion of the first restricting means, the connecting means controls the second driving means. Are driven to increase the engine speed. Therefore, the upper limit of the engine speed is regulated in two stages by the control of the control means, and the upper limit of the engine speed can be made different between the cargo handling operation and the traveling with a simple structure.

When the control means controls the contraction or extension of the connecting means when the accelerator pedal is not operated, the driving of the first driving means is regulated by the second regulating means, and the second driving means is regulated by the connecting means. Are driven to increase the engine speed. Therefore, when the accelerator pedal is not operated, the engine speed can be increased by controlling the control means.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of an idle adjustment device for an industrial vehicle, which is applied to a forklift that supplies a control oil pressure to a cylinder of a cargo handling device by an oil pump mounted with a diesel engine and driven by the engine. It is an example.

First, the configuration will be described. In FIG. 1, 21
Denotes a fuel injection pump for supplying fuel to a diesel engine (not shown), and the fuel injection pump 21 constitutes engine speed changing means for changing the engine speed. The fuel injection pump 21 is connected to an accelerator pedal 24 via a control lever 22 and an accelerator wire 23. The control lever 22 is rotatably supported with respect to the fuel injection pump 21 so that a fuel injection (not shown) inside the fuel injection pump 21 is performed. It is connected to the volume control. The control lever 22 is rotated by the accelerator operation of the accelerator pedal 24, and the fuel injection amount is increased by the rotation of the control lever 22 in the direction of arrow A in FIG. 1, and the fuel injection amount is increased by the rotation in the direction of arrow B in FIG. It is going to decrease. Therefore, the control lever 22 is operated by the accelerator pedal 24 and the fuel injection pump 21.
And drive means for driving the fuel injection pump 21 in accordance with the accelerator operation amount of the accelerator pedal 24.

Numeral 25 denotes a solenoid. The solenoid 25 has a first position indicated by a solid line in FIG. 1 and a second position indicated by a virtual line in FIG.
It has a drive shaft 25a that can move between positions. The drive shaft 25a can abut the control lever 22, and the contact with the control lever 22 restricts the rotation of the control lever 22 in the direction of arrow A in FIG.
Accordingly, the solenoid 25 has a drive shaft 25a movably provided between the first position and the second position and capable of contacting the drive means.
The contact means constitutes a regulating means for regulating the drive of the control lever 22 for increasing the engine speed. The drive of the drive shaft 25a of the solenoid 25 is controlled by a control means including a power supply 26 and a switch 27. When the switch 27 is turned on, the drive shaft 25a projects to the second position.

Here, the drive shaft 25a of the solenoid 25 is shown in FIG.
When the control lever 22 is located at the first position indicated by the solid line, the permissible amount of rotation of the control lever 22 in the direction of arrow A in FIG.
When the drive shaft 25a of the solenoid 25 is located at the second position indicated by the imaginary line in FIG. 1, the allowable rotation amount of the control lever 22 in the direction of arrow A in FIG. Therefore, the engine speed regulated when the drive shaft 25a of the solenoid 25 is located at the first position is different from the engine speed regulated when the drive shaft 25a of the solenoid 25 is located at the second position. Reference numeral 28 denotes a bracket fixed to a vehicle body (not shown). The bracket 28 supports the fuel injection pump 21 and the solenoid 25. A return spring 29 biases the accelerator pedal 24 in the direction of arrow D in FIG. Reference numeral 30 denotes a stopper which can be screwed to the fuel injection pump 21 and contact the control lever 22, and the idling rotation can be adjusted by adjusting the screwing amount of the stopper 30.

Here, controlling the engine speed to a predetermined speed higher than the normal idling speed during non-loading work is referred to as high idle control, and in this embodiment, as will be described later. It is possible to control the high idle control in two stages of low high idle and high high idle. Next, the operation will be described.

At the time of low-high idle control, the switch 27 is turned on, and the drive shaft 25a of the solenoid 25 projects to the second position indicated by the phantom line in FIG. As a result, the control lever
The amount of rotation in the direction of arrow A in FIG. 1 of FIG. 1 decreases, and the amount of depression of the accelerator pedal 24 decreases. Therefore, at the time of this low-high idle control, even if the accelerator pedal 24 is depressed, the engine speed is kept low.For example, by using this low-high idle control when the vehicle is running,
Low-speed running becomes easy.

At the time of high-high idle control, the switch 27 is turned off, and the drive shaft 25a of the solenoid 25 is retracted to the first position shown by the solid line in FIG. As a result, the amount of rotation of the control lever 22 in the direction of arrow A in FIG. 1 increases, and the amount of depression of the accelerator pedal 24 increases. Therefore, at the time of high-high idle control, depressing the accelerator pedal 24 causes an extremely high engine speed.For example, by using the high-high idle control at the time of cargo handling, the engine-driven pump is used for cargo handling. The supplied hydraulic pressure is sufficiently increased.

As described above, the drive shaft 25a of the solenoid 25
Is controlled by turning on / off the switch 27, and the engine speed, which is regulated when the drive shaft 25a is located at the first position, is regulated when the drive shaft 25a of the solenoid 25 is located at the second position. Engine speed.
For this reason, it is possible to regulate the upper limit of the engine speed in two stages by the control of the control means, that is, to control the high idle control to two stages of low high idle and high high idle, for example, during loading and unloading work and The upper limit of the engine speed during traveling can be different from each other. Further, the simple configuration of the control lever 22, the solenoid 25, and the like makes it possible to regulate the upper limit of the engine speed in two stages, so that a complicated link mechanism and the like can be eliminated, and the device can be downsized. And can be simplified. Therefore, it is possible to reduce the size and simplification of the apparatus while enabling sufficient hydraulic pressure to be supplied during cargo handling and facilitating low-speed traveling during traveling.

FIG. 2 is a view showing one embodiment of an idle adjusting device for an industrial vehicle according to the first aspect of the present invention. As in the previous embodiment, a diesel engine is mounted and oil driven by this engine is used. This is an example in which the present invention is applied to a forklift for supplying a control oil pressure to a cylinder of a cargo handling device by a pump. In FIG. 2, the same members as those of the embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

First, the configuration will be described. In FIG. 2, 31
Is a lever connected to an accelerator pedal 24 via an accelerator wire 23, and the lever 31 is rotatably supported by a bracket 32 fixed to a vehicle body (not shown). The lever 31 is rotated in the directions indicated by arrows E and F in FIG. 2 according to the accelerator operation amount of the accelerator pedal 24, and constitutes a first driving unit. Reference numeral 33 denotes a control lever. The control lever 33 is connected to the fuel injection pump 21 by an arrow G in FIG.
The fuel injection pump 21 is rotatably supported in the H direction and is connected to a fuel injection amount adjustment unit (not shown) in the fuel injection pump 21. Therefore, the control lever 33 constitutes second driving means capable of driving the fuel injection pump 21. The direction of arrow G in FIG. 2 of the control lever 33 is a direction for increasing the fuel injection amount, and the direction of arrow H in FIG. 2 is a direction for decreasing the fuel injection amount.

The lever 31 and the control lever 33 are connected by a solenoid 34, that is, the main body of the solenoid 34 is supported by the lever 31, and the drive shaft 34a of the solenoid 34
Is connected to the control lever 33. The drive shaft 34a projects from the main body of the solenoid 34 when the switch 27 is turned off, and is retracted when the switch 27 is turned on. Therefore,
The solenoid 34 connects the lever 31 and the control lever 33, and constitutes extendable connecting means for interlocking the lever 31 and the control lever 33. The switch 27 and the power supply 26 constitute control means for controlling the driving of the solenoid 34.

The bracket 32 supports the fuel injection pump 21 and also supports a stopper 35.
Has a contact portion 35a that can contact the lever 31, and regulates the rotation of the lever 31 in the direction of arrow E in FIG. Therefore, the stopper 35 is brought into contact with the contact portion 35a and the lever 31,
A first regulating means for regulating the driving of the first driving means for increasing the engine speed is constituted. A stopper 36 is supported on the bracket 32. The stopper 36 has a contact portion 36a that can contact the lever 31 when the accelerator pedal 24 is not operated by the accelerator. Restrict rotation. Therefore, the stopper 36 constitutes second restricting means for restricting the driving of the lever 31 for lowering the engine speed by the contact between the contact portion 36a and the lever 31.

Here, when the lever 31 is kept in contact with the contact portion 35a of the stopper 35 by the accelerator operation of the accelerator pedal 24, and when the switch 27 is turned on, the solenoid 34 is controlled to contract. ,solenoid
The control lever 33 is driven so as to increase the engine speed in the direction of arrow G in FIG. Further, when the accelerator pedal 24 is not operated, the lever 31 comes into contact with the contact portion 36 of the stopper 36 by the urging force of the return spring 29. In this state, when the solenoid 34 is controlled to contract by turning on the switch 27,
The rotation of the lever 31 is regulated by a stopper 36, and the control lever 33 is driven by a solenoid 34 so as to increase the engine speed in the direction of arrow G in FIG.

The bracket 32 is fixed to a vehicle body (not shown), and the fuel injection pump 21 abuts on the control lever 33 during idling to restrict the rotation of the control lever 33 in the direction of arrow H in FIG. stopper
37 is screwed, and the idling rotational speed is adjusted by adjusting the screwing amount of the stopper 37. Note that, also in the present embodiment, low high idle control and high high idle control can be performed as in the example of FIG.

Next, the operation will be described. During low-high idle control, the switch 27 is turned off and the drive shaft of the solenoid 34 is turned off.
The control lever 33 is turned in the direction of arrow H in FIG. The amount of fuel supplied by the fuel injection pump 21 depends only on the amount of rotation of the lever 31. As a result, the lever
Even if the accelerator pedal 24 is depressed until the abutment 31 abuts on the abutment portion 35a of the stopper 35, an increase in the fuel injection amount of the fuel injection pump 21 is prevented. Therefore, at the time of low-high idle control, the engine speed is kept low even when the accelerator pedal 24 is depressed. For example, when the low-high idle control is used during vehicle running, low-speed running of the vehicle is facilitated.

During high-high idle control, the accelerator pedal 24 is depressed until the lever 31 contacts the contact portion 35a of the stopper 35, and the switch 27 is turned on. As a result, the drive shaft 34a of the solenoid 34 is retracted, and the control lever
33 is further rotated in the direction of arrow G in FIG. 2, and the fuel injection amount of the fuel injection pump 21 increases. Therefore, during high-high idle control, the accelerator pedal 24 is depressed and the switch
By turning on 27, the engine speed becomes extremely high.For example, when high-high idle control is used during cargo handling work, the hydraulic pressure supplied from the engine driven pump for cargo handling work is sufficiently increased. You.

On the other hand, in this embodiment, when the switch 27 is turned on when the accelerator pedal 24 is not operated by the accelerator,
Since the rotation of the lever 31 in the direction of arrow F in FIG. 2 is restricted by the stopper 36a, the control lever 33 is rotated in the direction of arrow G in FIG. 2 by the solenoid 34, and the fuel injection amount of the fuel injection pump 21 increases. As a result, the engine speed increases. That is, this embodiment includes a so-called idle-up FICD (fast idle control device). In this embodiment, when the drive shaft 34a of the solenoid 34 is retracted, the control lever 33 rotates in the direction in which the engine speed increases. However, the solenoid 34 is rotated by the rotation center of the lever 31 and the control lever 33. , The control lever 34 may rotate in the direction in which the engine speed increases when the drive shaft 34a of the solenoid 34 protrudes.

As described above, in the present embodiment, the accelerator 27 of the accelerator pedal 24 holds the switch 27 while maintaining the contact state between the lever 31 and the contact portion 35a of the stopper 35.
When the solenoid 34 is controlled to contract by turning on, the control lever 33 is rotated by the solenoid 34 so as to increase the engine speed. Therefore, by turning on / off the switch 27, the upper limit of the engine speed can be limited to two stages, that is, two stages of low high idle and high high idle can be controlled. Also, the upper limit of the engine speed for increasing the engine speed during traveling can be different from each other. In addition, since the upper limit of the engine speed is regulated in two stages by a simple configuration of the lever 31, the control lever 33, the solenoid, and the like, a complicated link mechanism and the like can be made unnecessary, and the device can be downsized. And can be simplified. Therefore, it is possible to reduce the size and simplification of the apparatus while enabling sufficient hydraulic pressure to be supplied during cargo handling and facilitating low-speed traveling during traveling.

Further, when the accelerator pedal 24 is not operated, the lever 31 comes into contact with the contact portion 36 of the stopper 36 by the urging force of the return spring 29. In this state, when the solenoid 34 is controlled to contract by turning on the switch 27, the rotation of the lever 31 is restricted by the stopper 36, and the control lever 33 is driven by the solenoid 34 to increase the engine speed. For this reason, the present embodiment can also add the FICD function as described above.

Further, in the present embodiment, when shifting from low-high idle to high-high idle control, or when shifting from high-high idle to low-high idle control, that is, while the accelerator pedal 24 is depressed, the switch 27 When switching between on and off, the engine speed can be changed without changing the amount of depression of the accelerator pedal 24. Therefore, it is possible to prevent a feeling of strangeness from occurring in the accelerator operation. The operability of the accelerator operation can be improved.

Incidentally, the invention described in claim 1 is not limited to the above-described examples, and it goes without saying that the embodiments of each means may be other as long as they are obvious.

[0034]

【The invention's effect】

According to the first aspect of the present invention, the connecting means is contracted by the control means in a state where the contact between the first driving means and the contact portion of the first regulating means is held by the accelerator operation of the accelerator pedal. Or when controlled to stretch,
Since the second driving means is driven by the connecting means so as to increase the engine speed, the upper limit of the engine speed can be limited to two stages under the control of the control means, and the engine speed during the loading operation and during the traveling can be controlled. Can be different. Therefore, sufficient hydraulic pressure can be supplied at the time of cargo handling, and at the time of traveling, low-speed traveling can be facilitated, and the device can be reduced in size and simplified.
Further, when the control means controls the contraction or expansion of the connection means during the non-acceleration operation of the accelerator pedal, the second drive means is driven by the connection means to increase the engine speed. During operation, the engine speed can be increased by control of the control means.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an idle adjustment device for an industrial vehicle.

FIG. 2 is a diagram showing a schematic configuration of an embodiment of an idle adjusting device for an industrial vehicle according to the invention of claim 1;

FIG. 3 is a diagram showing a conventional industrial vehicle idle adjustment device.

[Explanation of symbols]

 21 Fuel injection pump (engine rotation speed varying means) 22 Control lever (driving means) 24 Accelerator pedal 25 Solenoid (regulating means) 25a Drive shaft (abutting part of regulating means) 26 Power supply, 27 Switch (control means) 31 Lever ( First drive means) 33 Control lever (second drive means) 34 Solenoid (connection means) 35 Stopper (first control means) 35a Contact part (contact part of first control means) 36 Stopper (second control means) 36a Contact part (contact part of 2nd regulation means)

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Claims (1)

(57) [Claims] 1. An engine speed changing means for changing an engine speed, a first driving means connected to an accelerator pedal and driven in accordance with an accelerator operation amount of the accelerator pedal, and an engine speed changing means connected to the engine speed changing means. A second driving means capable of driving the engine speed varying means, an extendable connecting means for connecting the first driving means and the second driving means and interlocking the first driving means and the second driving means, A first restricting means having a contact portion capable of contacting the driving means, and restricting the driving of the first driving means in a direction to increase the engine speed by the contact of the contact portion and the first driving means; A contact portion that comes into contact with the first drive means when the pedal is not operated by the accelerator, and the contact between the contact portion and the first drive means restricts the drive of the first drive means in the direction of decreasing the engine speed. 2 And control means, in a state where the contact is maintained between the contact portion of the first drive means and the first regulating means by the accelerator operation of the accelerator pedal,
When the connecting means is controlled to shrink or expand,
When the second driving means is driven by the connecting means to increase the engine speed, and when the connecting means is controlled to contract or extend when the accelerator pedal is not operated by the accelerator, the driving of the first driving means is controlled by the second regulating means. And a drive control means for driving the second drive means to increase the engine speed by the connection means.