JPH0658453A - Proportional valve operating mechanism - Google Patents

Abstract

PURPOSE:To provide a proportional valve operating mechanism operable in the same operating method as a lever of a manual selector valve. CONSTITUTION:A lever 5a is installed in an operator of a fork lift or the like. In addition, this proportional valve operating mechanism is provided with a support part supporting this lever 5a free of rotation, a rod 5d being connected to the lever 5a and doing its rectilinear motion with its rotation, a spring 5f giving the rod 5d such a force as putting the lever 5a back to neutrality, two microswitches 5b1, 5b2 detecting a rotational direction of the elver 5a, and a sensor 5c detecting an amount of travel of the rod 5d doing the rectilinear motion, respectively. With this constitution, according to operation of the lever 5a, it can control a proportional valve by each detecting signal being obtained from these microswitches 5b1, 5b2 and the sensor 5c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proportional valve operating mechanism suitable for an operator of a forklift or the like.

[0002]

2. Description of the Related Art FIG. 5 is a side view showing the structure of a forklift 1. In this figure, reference numeral 5 is a valve operating portion, which has levers 5a, 5a that can be operated in the front, rear, left and right directions. Each lever 5a moves up and down the fork 2, tilts the mast 3 forward / backward,
And other manual switching valves that control the mechanisms that operate the attachments. In the driver's seat, the operator can operate the forks 2 and the mast 3 to perform cargo handling work by operating these levers. FIG. 6A is a plan view of the valve operating unit 5,
FIG. 6B is a side view of the valve operating unit 5. The valve operating portion 5 is composed of two levers 5a, 5a and a portion associated with each lever. Since the portions related to each of the levers 5a and 5a have the same configuration, only the portion related to one lever 5a will be described below. The lever 5a is rotatably attached to the forklift body by a rotation shaft 5e. Reference numeral 5b denotes a micro switch, which is used when the lever 5a rotates in the direction of arrow a.
When the end of a comes into contact, it is turned on. When the micro switch 5b is turned on, the motor that is the drive source of the hydraulic pressure generation pump is activated. Further, the lever 5a and the spool of the manual switching valve (not shown) are connected to the rod 5
It is directly connected via d. Here, when the lever 5a is operated in the arrow A direction, the rod 5d moves in the arrow B direction,
The spool is driven by the movement of the rod 5d. As a result, the hydraulic output is controlled according to the operation amount of the lever 5, and the cargo handling work is performed. By the way, in recent years, as a control valve for a forklift, a proportional valve using the attractive force of an electromagnet (solenoid) has been used instead of the above-mentioned manual switching valve. A joystick has been conventionally used as an operator of this type of proportional valve. By operating the joystick, the operator can turn on / off the electric signal to the proportional valve to freely control the oil flow direction and the hydraulic pressure output. Therefore, it is possible to easily operate the forklift.

[0003]

By the way, in the lever operation for controlling the manual switching valve and the joystick operation for controlling the proportional valve, the former requires arm force, whereas the latter does not require arm force. For example, the operation mode is extremely different. Therefore, there is a problem that it is difficult for an operator who is accustomed to controlling the manual switching valve by operating the lever to perform proportional valve control by operating the joystick. The present invention has been made under such a background, and an object thereof is to provide a proportional valve operating mechanism that can be operated by the same operating method as a lever of a manual switching valve.

[0004]

A proportional valve operating mechanism according to the present invention comprises a lever, a support portion for rotatably supporting the lever, and a linear motion connected to the lever, the linear movement being associated with the rotation of the lever. A micro switch for detecting the rotation of the lever, and a sensor for detecting the amount of movement of the linearly moving rod. And controlling the proportional valve by a detection signal obtained from the sensor.

[0005]

According to the above structure, a signal for controlling the proportional valve can be obtained by the same operation as the lever operation for controlling the manual switching valve.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a proportional valve operating mechanism according to an embodiment of the present invention. In this figure, those parts corresponding to those in FIG. 6 are designated by the same reference numerals, and a description thereof will be omitted. The valve operating unit 5 shown in FIG. 6 has only the micro switch 5b, but the proportional valve operating unit 50 has two micro switches 5b for detecting the rotation of the operating lever 5.
₁ and 5b ₂ . When the lever 5a is in the neutral state, all the micro switches are in the off state. When the lever 5a is rotated in the arrow b direction from the neutral state, the micro switch 5b ₁ is turned on by the end of the lever 5a is in contact. As a result, a start signal for starting the motor that is the drive source of the hydraulic pressure generating pump and a control signal for opening the port corresponding to the micro switch 5b ₁ of the ports of the proportional valve are output. On the other hand, when the lever 5a is rotated in a direction opposite to the arrow b direction, becomes microswitch 5b ₂ is turned on, an activation signal, a control signal for opening the port corresponding to the micro switch 5b ₂ is output It One end of the rod 5d is the lever 5
a and the other end is operated by a spring 5f.
It is fixed to the body. When the lever 5a is rotated from the neutral state, the rod 5d is interlocked with this and the rod 5d moves in the arrow B direction or the opposite direction. At this time, a force against this movement is generated by the spring 5f. Therefore, the rod 5
d is always biased to return to the neutral state. Further, the proportional valve operating unit 50 has a mechanism for detecting the amount of movement of the rod 5d. The details will be described below. First, as shown in FIG. 2, the rod 5d has pins 5 on both sides.
d ₁ and 5d ₂ are mounted in a staggered manner. These pins are placed on the rod 5d at an eccentric position as shown in FIG.
It has a male screw that fulfills the connection with. With such a configuration, the effective mounting position of each pin in the rod longitudinal direction can be adjusted by adjusting the amount of screwing when mounting on the rod 5d. The sensor 5c in FIG. 1 detects the amount of movement of the rod 5d based on the behavior of the pins 5d ₁ and 5d ₂ , and FIG. 3 is a perspective view thereof. As shown in FIG. 3, the sensor 5c has a rotating portion 5e that can rotate only in the arrow C direction. This rotating part 5
The e has claws 5e ₁ and 5e ₂ at both ends thereof. When the rod 5d moves from the neutral position in the direction of arrow B, the pin 5d ₁ is pressed against the claw 5e ₁ so that the rotating portion 5
e rotates in the direction of arrow C. Further, when the rod 5d moves from the neutral position in the direction of arrow D, the pin 5d2 moves toward the claw 5e2.
Be pressed against. Also in this case, the rotating portion 5e rotates in the arrow C direction.

According to this structure, when the operator operates the lever 5a in the direction of arrow A, the micro switch 5b ₁ is turned on, the port corresponding to this switch in the proportional valve is opened, and the hydraulic pressure generating pump is opened. The driving motor is started. Then, the rod 5d moves in the arrow B direction as the lever 5a rotates. Here, when the rod 5d moves, a repulsive force is generated by the spring 5f, and this repulsive force is transmitted to the lever 5a via the rod 5d. Therefore, the operator can rotate the lever 5a while feeling the response. During this time, the rotating portion 5e is rotated by the pin 5d ₁ as the rod 5d moves. As a result, the sensor 5c outputs a control signal having a value corresponding to the rotation amount of the rotating portion 5e, that is, the operation amount of the lever 5a. Then, the control signal controls the opening area of the port corresponding to the microswitch 5b ₁ . Thereafter, when the operator releases the lever 5a, the lever 5a is returned to the neutral state by the spring 5f. Even when the operator operates the lever 5a in the direction opposite to the arrow A direction, the same operation as described above is performed.

In the present embodiment, one sensor is provided for one lever and used to control two ports. However, two sensors are provided for each port for convenience and one lever is provided. It may be controlled by operation,
The correspondence between ports and sensors is not particularly limited.

[0009]

As described above, according to the present invention,
A lever and a support portion that rotatably supports the lever,
A rod that is connected to the lever and that moves linearly with the rotation of the lever; a spring that applies a force for returning the lever to a neutral state to the rod; and a microswitch that detects the rotation direction of the lever, A proportional valve is controlled by the same lever operating method as the lever of the manual switching valve, since a proportional valve is controlled by a detection signal obtained from the microswitch and the sensor. Can be controlled.

[Brief description of drawings]

FIG. 1 is a plan view and a side view of a proportional valve operating portion according to an embodiment of the present invention.

FIG. 2 is a perspective view of a rod in the same embodiment.

FIG. 3 is a perspective view of a sensor in the example.

FIG. 4 is a side view and a front view of a pin in the same embodiment.

FIG. 5 is a perspective view of a general forklift.

FIG. 6 is a plan view and a side view of a conventional valve operating portion.

[Explanation of symbols]

50 ...... proportional valve operating portion 5a ...... lever 5b _1, 5b ₂ ...... microswitch 5c ...... sensor 5d ...... rod 5f ...... spring

Claims (1)

[Claims] 1. A lever, a support portion that rotatably supports the lever, a rod that is connected to the lever and that moves linearly with the rotation of the lever, and a force that returns the lever to a neutral state. A spring provided to the rod, a microswitch that detects a rotation direction of the lever, and a sensor that detects a moving amount of the rod that moves linearly are provided, and a proportional relation is obtained by a detection signal obtained from the microswitch and the sensor. A proportional valve operation mechanism characterized by controlling a valve.