JPS6233657Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power tail control operation lever for tilting or returning the cab in a cab-over type automobile in which the driver's cab (hereinafter referred to as the cab) is folded forward.

Hereinafter, the conventional technology that is the premise of the present invention will be explained.

Many automobiles, such as trucks, in which the engine is located below the driver's cab, are of the so-called cab-over type, and are equipped with a mechanism that allows the cab to be moved forward for inspection or repair of the engine. In order to tilt the driver's cab forward with respect to the vehicle body frame, a cab tail cylinder, which is usually a hydraulic cylinder, is provided, and an electric pump that supplies pressure oil is connected to this cab tail cylinder. ing. Between this electric pump and the cab tail cylinder, there is a hydraulic circuit that extends the cab tail cylinder and tilts the cab forward, and a hydraulic circuit that retracts the cab tail cylinder and returns the tilted cab to its original state. Two hydraulic circuits are interposed, a return hydraulic circuit, and the electric pump is equipped with a hydraulic circuit switching valve for switching between these two hydraulic circuits.

In FIG. 1, the hydraulic switching valve is indicated by reference numeral 1, and switching is controlled in accordance with rotation of an operating lever indicated by reference numeral 2 in FIG. 2 about the zero point.

For example, if the operating lever 2 is in the position shown by the imaginary line in FIG. 2, the valve 1a of the hydraulic circuit switching valve 1 is in a state of forming a hydraulic circuit. At this time, the hydraulic circuit of the electric pump P is in a state where the piston of the cab tail cylinder 3 can be moved in the direction indicated by the arrow D, and the cab operates in the return direction in accordance with the movement in the D direction. I am made to do so.

Hereinafter, the position of the operating lever 2 in this position will be referred to as the return operating position.

Next, in FIG. 2, when the operating lever 2 is rotated clockwise from the return operating position, the hydraulic switching valve 1 goes through a neutral state in which the valve 1c constitutes the hydraulic circuit, and then the valve 1b enters the hydraulic circuit. The operating lever 2 reaches the tilt operating position shown by the solid line. In this tilt operation position, the valve 1b of the hydraulic circuit switching valve 1 is in a state of forming a hydraulic circuit. At this time, the hydraulic pressure of the electric pump P is in a state where the piston of the cab tail cylinder 3 can be moved in the cab tilting direction indicated by the arrow U, and the cab tilts forward in accordance with the movement in the U direction. Operated in the direction.

It is assumed that the electric pump P is connected to a motor M and is driven according to the rotation of the motor M.

In FIG. 3, the base end 3a of the cylinder 3 is pivotally supported by the vehicle body frame, and the bracket _3b1 at the upper end of the piston rod 3b is pivotally supported by the cab.
At the top of the cylinder 3, a fitting 3c is provided integrally with the cylinder 3. A cylinder maximum contraction detection switch SW ₁ and a tilt completion detection switch SW ₂ are attached to this fixture 3c. On the other hand, a stay 5 is attached to the upper part of the piston rod 3b, and its lower bent portions 51 and 52 have the function of operating each of the above-mentioned switches.

That is, when the cab is in the return completion state, the bending portion 51 presses the cylinder maximum compression detection switch _SW1 , and this press turns the switch off. Therefore, when there is no pressing force, for example when the cab is tilted forward, the on state is maintained.

Next, when the cab is in a predetermined forward tilting completion state, the bending portion 52 switches to the tilt completion detection switch SW ₂
This press turns the switch off. Therefore, when there is no pressing force, for example, when the cab is in the process of tilting forward (or in the process of returning), the on state is maintained.

In the motor drive circuit shown in FIG. 4, the cylinder maximum compression detection switch SW ₁ and the tail completion detection switch SW ₂ are connected in parallel with each other, and the changeover valve switch SW ₃ is connected to the cylinder maximum compression detection switch SW _1.
and the tail completion detection switch _SW2 are provided with a switching function that always selects the circuit that passes through either one of them. Here, turn the cylinder maximum contraction detection switch SW ₁
The state in which the tilt completion detection switch SW2 is switched to the side is called a down state, and the state in which it is switched to the tilt completion detection switch _SW2 side is called an up state. Note that a tail switch _SW4 is interposed in the motor drive circuit.

Conventionally, as shown in FIG.
SW ₃ is switched to the up state when pressed by the pressing piece 2a integrated with the operating lever 2 when the operating lever 2 is rotated to the tilt operating position,
At other times, it will remain in a down state.

Here, consider the operation of tilting the cab forward from the fully restored state. First, assuming that the tilt switch SW ₄ is set to ON due to the configuration for which explanation is omitted, turn the operating lever 2 to the tilt operation position shown by the solid line in Fig. 2 and turn the directional valve switch SW ₃ on. maintain the condition.

Then, in response to the rotation of the operating lever 2, the valve 1b (see FIG. 1) forms a hydraulic circuit as described _above , and in FIG. Completion detection switch
Since SW ₂ is on, relay 6 is also on, motor M starts driving, electric pump P is driven, hydraulic pressure is applied, piston rod 3b rises, and the cab starts tilting forward.

Then, when the bending section 52 presses the tilt completion detection switch _SW2 , the switch is turned off and the motor M is stopped accordingly. Incidentally, at this time, the cylinder maximum contraction detection switch _SW1 is turned on.

In the conventional technology, if the pressing state of the directional valve switch SW ₃ by the operating lever 2 is unstable, the switch switches to the down state, and the motor M is driven even though it is not necessary, wasting energy. It is uneconomical as it is wasted.

Then, the operation lever 2 as shown in FIG.
When the directional valve switch is pressed continuously in the rotating direction,
In a configuration in which SW ₃ is pressed, the pressing state of the switch is unstable, resulting in the wasteful consumption of energy as described above.

The present invention was developed by focusing on the above-mentioned problems of the conventional technology, and it is designed to provide a power tail control lever that can maintain a constant pressure on the switch and is easy to operate with fewer malfunctions. The purpose is to provide operations for power tail control.

An embodiment will be explained with reference to FIGS. 5 to 7.

In the figure, a power tail control operating lever 200 is supported by, for example, a spherical bearing so as to be rotatable about a zero point. Also, like the operating lever 2, it is assumed that it is interlocked with the hydraulic switching valve 1. A half-moon-shaped plate 210 is integrally fixed to the base end of the operating lever 200 by means such as welding. Here, the plate 210 and the free end of the operating lever 200 are in a relationship similar to the bottom of a frying pan and the handle of a frying pan in terms of the mounting angle, and the free end of the operating lever 200 is relative to the plate surface. It has a slope.

Therefore, when the operation lever 200 is attached to the holder 7 at the return operation position, the plate 2
10 is inclined with respect to the casing wall 8 covering the motor M and the electric pump P, and is therefore spaced apart from the tail switch SW ₄ .

A part of the arcuate outer peripheral surface of the plate 210 includes
A band-shaped push plate 210a is formed along the circumferential surface of the push plate 210a as shown in FIG. A circular arc surface 220 is formed.

In this example, the power tail control operating lever 200 is mounted on a holder 7 that holds the operating lever.
When the plate 210 presses (turns on) the tail switch SW ₄ ,
Further withdrawal operations are restricted. This is because the push plate 210a comes into contact with the wall surface 8. In other words, the push plate 210a also has a function as a stopper to prevent the tail switch SW ₄ from being pushed excessively and damaged. The guide member 9 has the function of preventing the operating lever 200 from returning during the operating process and maintaining the pressure of the tail switch SW ₄ . In the operating range where the free end of the operating lever 200 is guided by the guide member 9,
The plate 210 is rotated while maintaining a state substantially parallel to the wall surface 8.

A stopper 9a is provided at the lower end of the guide member 9 to prevent the operation lever from rotating beyond a position corresponding to the solid line in FIG. A recess 9b is formed. Further, a holder 10 is attached to the wall surface 8.

Therefore, if the operating lever 200 is held in a position where it contacts the stopper 9a with the operating lever 200 pulled out toward the front, the directional valve switch _SW3 will be pressed by the switch operating surface 220 and the hydraulic circuit will be activated. Since the up state is maintained and the tail switch SW ₄ is turned on, the cab is tilted forward.

When the forward tilting of the cab is completed, the tilt completion switch SW ₂ (see Figure 3) is turned off and the motor M is stopped. However, if the pressure of the directional valve switch SW ₃ is unstable, If so, the motor M and the electric pump P may be driven unnecessarily. However, as in this example, the switch operation surface 220 holds the switch SW ₃ in a pressed state near the tilt operation position, so the tilt completion switch SW ₂
As long as is off, motor M will not be driven. Therefore, electric pump P is also not driven.

After the cab has been tilted forward, the free end of the operating lever 200 is attached to the recess 9b and the holder 10. Due to this mounting operation, the plate 210 is tilted from the wall surface 8, and the plate 210 is separated from the tail switch _SW4 , thereby turning off the switch.

Note that the formation area of the switch operation surface 220 is 0.
For example, move the operation lever 200 within a range of 10 degrees from the tilted operation position, centering on the point, and turn the directional valve switch.
Set so that SW ₃ can be pressed. In this case the above
Even if the operating lever is swung within a range of 10 degrees, the electric pump will not be driven unnecessarily.

As described above, according to the present invention, even if the operating lever swings slightly from the predetermined tilt operating position due to the driver's carelessness, etc., the functional state of the switch will not change, which causes the problems of the prior art described above. The points will be cancelled.

In addition, when the forward tilting and return of the cab is completed, the tail switch SW4 can be activated by rotating the operating lever in a direction approximately perpendicular to the operating direction of the hydraulic circuit switching valve.
Since the motor drive circuit is disconnected and the cab is maintained in its state, the cab can be tilted forward and returned to its original position easily and reliably without malfunction using a single operation lever.

[Brief explanation of the drawing]

Figure 1 is a hydraulic circuit diagram for power tail control.
Figure 2 is a front view of a conventional power tail control operating lever, Figure 3 is a front view of a cab tail cylinder, Figure 4 is a motor drive circuit diagram for power tail control, and Figure 5 is a front view of a conventional power tail control lever. A front view of the power tail control operating lever section illustrating an embodiment of the present invention,
FIG. 6 is a perspective view of a power tail control operating lever portion explaining an embodiment of the present invention, and FIG. 7 is a sectional view of a push plate portion. 200...Operation lever for power tail control,
220...Switch operation surface, SW ₃ ...Direction valve switch.

Claims (1)

[Scope of utility model registration request] an electric pump that supplies pressure oil to the cab tail cylinder via a hydraulic circuit; a hydraulic circuit switching valve that switches the direction of supply of pressure oil to the cab tail cylinder to switch between tilting or backward movement of the cab; an operating lever that is rotated to switch the hydraulic circuit switching valve and is also rotatably supported in a direction substantially perpendicular to the rotational direction; a plate that operates a tail switch for starting and stopping the electric pump by rotation in a direction substantially perpendicular to the rotation direction for switching the hydraulic circuit switching valve by an operating lever; and a plate provided at an end of the plate. and is formed by an arcuate surface centered on the rotation center of the operating lever that is rotated to switch the hydraulic circuit switching valve, and is responsive to the rotation of the operating lever that is rotated to switch the hydraulic circuit switching valve. An operation lever for power tail control, characterized by having a switch operation surface for operating a changeover valve switch.