JPS6246621Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an operating lever for power tilt control.

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 tilt cylinder, which is usually a hydraulic cylinder, is provided, and an electric pump that supplies pressurized oil is connected to this cab tilt cylinder. . Between this electric pump and the cab tilt cylinder, there is a hydraulic circuit that extends the cab tilt cylinder and tilts the cab forward, and a hydraulic circuit that retracts the cab tilt cylinder and returns the tilted cab to its original state. Two systems of hydraulic circuits are interposed, and the electric pump is equipped with a hydraulic circuit switching valve for switching between these two systems of hydraulic circuits.

In FIG. 1, the hydraulic switching valve is indicated by reference numeral 1, and switching is controlled by an operating lever indicated by reference numeral 2 in FIG. The operating lever 2 is pivotally supported by a shaft 4 via a pin 5, which is pivotally supported by a bracket 3. Further, a flat plate 6 is fixed to the tip of the operating lever 2, and an arc-shaped flange member 7 is attached to the edge of the flat plate.
is fixed. The bracket 3 also includes a changeover switch _SW1 which is the first switch shown in FIG.
and the main switch SW ₂ , which is the second switch, are installed. The main switch SW 2 is turned on when the operating lever 2 is rotated from the imaginary line position around the pin 5 to the solid line position where the flange member 7 abuts the bracket ₃ in FIG. ing. Further, when 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 tilt cylinder 8 can be moved in the direction indicated by the arrow D, and in response to the movement in the direction D, the cab is operated in the return direction. It will be done.

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 forms a hydraulic circuit, and then the valve 1b forms a hydraulic circuit. However, the operating lever 2 reaches the tilting 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 tilt cylinder 8 can be moved in the cab tilting direction indicated by the arrow U, and in response to the movement in the U direction, the cab is tilted forward. is activated.

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. 5, the base end 8a of the cylinder 8 is pivotally supported on the vehicle body frame, and the bracket _8b1 at the upper end of the piston rod 8b is pivotally supported on the cab.
At the top of the cylinder 8, a fitting 8c is provided integrally with the cylinder 8. A cylinder maximum contraction detection switch _SW3 and a tilt completion detection switch _SW4 are attached to this fixture 8c. On the other hand, a stay 9 is attached to the upper part of the piston rod 8b, and its lower bent portions 91 and 92 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 91 presses the cylinder maximum compression detection switch _SW3 , 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 the predetermined forward tilting completion state, the bending portion 92 presses the tilt completion detection switch _SW4 , and this pressing 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 ₃ and the tilt completion detection switch SW ₄ are connected in parallel with each other, and the changeover switch SW ₁ is connected to the cylinder maximum compression detection switch SW ₃ and the tilt completion detection switch. It is equipped with a switching function that always selects the circuit that passes through either SW ₄ . Here, the state in which the cylinder retraction detection switch SW ₃ is switched to the side is referred to as a down state, and the state in which it is switched to the tilt completion detection switch SW ₄ side is referred to as an up state.

Conventionally, as shown in FIG.
SW ₁ is switched to the up state when pressed by the flange member 7 integrated with the operating lever 2 when the operating lever 2 is rotated to the tilt operating position, and otherwise maintains the down state. It's becoming like that.

Here, consider the operation of tilting the cab forward from the fully restored state. First, the main switch SW ₂ is turned on by moving the operating lever 2 to the solid line position in Figure 2, and then turning the operating lever 2 to the tilt operating position shown by the solid line in Figure 2 to turn on the changeover switch SW _1.
remain on.

Then, in response to the rotation of the operating lever 2, as explained above, the valve 1b (see Fig. 1) forms a hydraulic circuit, and in Fig. 4, the changeover switch SW ₁ is in the up state, and the tilt is completed Since the detection switch SW ₄ is in the on state, the relay 10 is also turned on, the motor M starts driving, the electric pump P is driven, hydraulic pressure is applied, the piston rod 8b rises, and the cab starts tilting forward. .

Then, the bending portion 92 activates the tilt completion detection switch.
When SW ₄ is pressed, the switch is turned off, and the motor M is stopped accordingly. Furthermore, at this time,
The cylinder most compressed detection switch SW ₃ is turned on.

In the above conventional structure, the operating lever 2 is
Move the main switch SW 2 around the pin 5 from the position shown by the phantom line in the figure to the solid line position where the flange member 7 abuts the bracket 3, and turn on the main switch SW _2. In this state, the operating lever 2 is further turned on as shown by the phantom line in Fig. 2. Since the bracket 3 was moved around the shaft 4 from the position shown by the solid line and the changeover switch SW ₁ was turned on, there was a problem in that the paint on the bracket 3 peeled off over a wide area and the bracket 3 corroded. The present invention was devised to solve the above-mentioned problems, and embodiments of the present invention will be described in detail below with reference to FIGS. 6 and 7. Note that parts that are the same or substantially the same as those in the conventional structure are given the same reference numerals as in the conventional structure, and a description thereof will be omitted. Reference numeral 11 denotes a cylindrical member which is externally fixed to the shaft 4, and a lever 12 is fixed to the cylindrical member, and at the tip of the lever, when the pump M is stopped with the piston 8b extended, a piston is attached. A stopper (not shown) is provided to prevent 8b from descending, and a wire 13 is connected to the stopper for releasing the stopper. When the cab is not tilted, the operating lever 2 is held by a clamp 14 provided on the bracket 3, and in order to remove the operating lever 2 from the clamp, move the operating lever from the imaginary line position in Fig. 6 around the pin 5. When the main switch SW 2 is rotated counterclockwise, the stopper portion 15 of the operating lever 2 comes into contact with the outer peripheral surface of the cylindrical member 11, preventing further rotation and restricting the operating stroke of the main switch SW ₂ . . Next, while pressing the main switch SW _{2 with the operating lever 2} , rotate the operating lever until it comes into contact with the stopper member 16 fixed to the bracket 3 to turn on the changeover switch SW _1. When the cab is completely tilted, the operating lever is turned on. 2 is held by a clamp 17 provided on the bracket 3.

According to the above configuration, the operation stroke of the main switch SW ₂ is regulated by the stopper portion 15 of the operation lever 2.
Since this is done by abutting the bracket 3 with the cylindrical member 11, the paint film on the bracket 3 does not peel off, and the stopper portion 15 slides on the outer peripheral surface of the cylindrical member 11, but the sliding area is smaller than in the past. play.

[Brief explanation of the drawing]

Figure 1 is a hydraulic circuit diagram for power tilt control, Figure 2 is a front view of a conventional operating lever for power tilt control, Figure 3 is a side view of Figure 2, and Figure 4 is a motor for power tilt control. A drive circuit diagram, Fig. 5 is a front view of the cab tilt cylinder, Fig. 6 is a side view of the person in charge of Fig. 3 showing an embodiment of the present invention, and Fig. 7 is a perspective view showing an embodiment of the present invention. . 2: Operation lever, 4: Shaft, 5: Pin, 1
5: Stopper part.

Claims (1)

[Scope of utility model registration request] The electric pump that supplies fluid to the cab tilt cylinder via the fluid circuit is operated, and the first switch and the second switch connected in series switch the direction of supplying fluid to the cab tilt cylinder. In the device equipped with an operating lever for switching a fluid circuit switching valve that switches between tilting and returning, the operating lever is mounted on a shaft, and the operating lever is rotated around the axis of the shaft to switch the fluid circuit switching valve. The first switch is closed, and the operating lever is rotated about an axis substantially perpendicular to the shaft to close the second switch, and the operating lever is brought into contact with a stopper provided on the shaft. An operating lever for power tilt control, characterized in that the operating stroke of the second switch is regulated.