JP3115605U - Fluid control valve - Google Patents

Abstract

Provided is a fluid control valve capable of taking a space for easy operation of an emergency valve.
In a fluid control valve provided with an emergency valve 17 for lowering a lift when an electromagnetic solenoid valve 16 breaks down and enters a lift lock state, the emergency valve 17 is arranged close to the electromagnetic solenoid valve 16. And a position sensor 19 is disposed on the end face of the valve body perpendicular to the three axes of the spool via the bracket 18. As a result, the emergency valve 17 can be operated without interference with the position sensor 19 and the bracket 18.
[Selection] Figure 1

Description

  The present invention relates to a fluid control valve that controls supply and discharge of a high-pressure fluid to a lift cylinder by changing a fluid flow path by displacing a spool in a valve body.

  Conventionally, a hydraulic control device is used to drive a lift cylinder used in a lift device in a forklift truck. The fluid control valve is used in a hydraulic path from the hydraulic tank to the lift cylinder of this hydraulic control device. The operator displaces the spool by lever operation, and this displacement controls the flow path and flow rate of the fluid. I try to change it.

In particular, when the forklift truck uses a battery as a power source, it is necessary to minimize its consumption. Therefore, if the spool is in a position where the lift holds a fixed position, the fluid control valve In order to temporarily stop the drive motor of the hydraulic power source in order to minimize power consumption, a position sensor for detecting the position of the spool is provided at the terminal portion of the spool.
In addition, the forklift truck has a fluid control attached to a lift lock mechanism or the like that locks the movement of the lift by closing the passage from the lift cylinder to the hydraulic tank with an electromagnetic solenoid valve in order to prevent malfunction due to an erroneous operation by the operator Valves are also used. A plurality of these fluid control valves are used in a multiple connection in order to perform the operation normally required.

Japanese Patent Laid-Open No. 10-9429 JP 2001-187902 A

  The conventional fluid control valve is configured as described above. For example, when the battery-type forklift truck is equipped, a position sensor for detecting the position of the spool incorporated in the valve body is a bracket fixed to the valve body. Is attached. Further, when the electromagnetic solenoid valve is closed, a lift lock mechanism is provided that does not return the hydraulic fluid in the cylinder of the lift device to the hydraulic tank even if the spool is operated, that is, does not lower the lift device. When the electromagnetic solenoid valve fails in a forklift truck equipped with such a fluid control valve, there is a problem that the lift device cannot be operated and the lift cannot be lowered safely. For this reason, an emergency valve is attached so that the lift can be lowered even if the electromagnetic solenoid valve breaks down. However, the position sensor is attached to a bracket and is installed on the same plane as the emergency valve. There is a problem that an operation space such as the rotation of the valve shaft of the valve is not sufficient and the operation of the emergency valve is hindered.

  The present invention has been made in view of such circumstances, and the emergency valve can be easily operated without being interfered by the bracket to which the position sensor is attached, and the lift device can be lowered safely and reliably. An object of the present invention is to provide a fluid control valve that can be made to operate.

  In order to achieve the above object, the fluid control valve of the present invention is connected to a suction port for sucking high-pressure hydraulic fluid, a discharge port for discharging hydraulic fluid to the hydraulic fluid tank, and a cylinder port for sending high-pressure hydraulic fluid to the lift device. A valve body comprising: a sleeve to be opened; an electromagnetic solenoid valve that opens and closes a flow path between the cylinder port and the discharge port; and an emergency valve that forces the cylinder port to communicate with the discharge port when the electromagnetic solenoid valve fails; A switching unit that is incorporated in the sleeve so as to be able to advance and retreat, and that connects the cylinder port and the suction port to form a hydraulic fluid flow path, and a switching unit that connects the cylinder port and the discharge port to form a hydraulic fluid flow path. In the fluid control valve having a spool with the emergency valve, the emergency valve is juxtaposed in proximity to the electromagnetic solenoid valve and orthogonal to the spool shaft That the valve through the bracket to the body end face in which is disposed a position sensor for sensing the position of the spool.

  Therefore, the emergency valve can be operated without being interfered by the bracket for mounting the sensor.

  According to the present invention, even in a directional control valve that requires a bracket in the valve body, an additional function such as a lift lock mechanism and an emergency valve function can be realized easily and inexpensively. Moreover, even if this invention is implemented, since the space more than a prior art is not required, even if it arrange | positions in any position in a multiple valve | bulb, there exists the same effect. In other words, regardless of the shape of the bracket attached to the valve body of the present invention, it is suitably arranged so that the emergency valve can be operated reliably, and the emergency valve is also installed in the valve body attached with a bracket for a position sensor or the like. It is possible to provide a fluid control valve that can be easily equipped and does not impair the function of each other.

  The fluid control valve of the best mode provided by the present invention includes a suction port for sucking high-pressure hydraulic fluid, a discharge port for discharging hydraulic fluid to a hydraulic fluid tank, a cylinder port for sending high-pressure hydraulic fluid to a lift device, and these A valve body comprising a sleeve to which a port is connected, an electromagnetic solenoid valve that opens and closes a flow path between the cylinder port and the discharge port, and an emergency valve that forcibly communicates the cylinder port with the discharge port when the electromagnetic solenoid valve fails And a switch for connecting the cylinder port and the suction port to form a hydraulic fluid flow path, and a hydraulic fluid flow path by connecting the cylinder port and the discharge port. In the fluid control valve having a spool having a switching portion for performing the operation, the emergency valve is arranged in parallel with the electromagnetic solenoid valve, and the front Through the bracket to the valve body end face perpendicular to the spool shaft is disposed a position sensor for sensing the position of the spool.

  Hereinafter, embodiments of the fluid control valve of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a fluid control valve of the present invention installed in a battery-type forklift truck. 1A is a side cross-sectional view, and FIG. 1B is a rear view. This fluid control valve supplies a cylinder port 2 connected to the lift cylinder C and pressure oil from a hydraulic pump (not shown) to the cylinder port 2 and supplies pressure oil in the cylinder port 2 to a hydraulic tank (not shown). And a spool body 3 that is slidably accommodated in a sleeve 7 formed in the valve body 1 and that switches between the passages. An electromagnetic solenoid valve 16 for use in a lift lock mechanism that prevents malfunction such as lowering of the lift device, a battery by detecting the position of the emergency valve 17 for lowering the lift when the electromagnetic solenoid valve 16 breaks down and the position of the spool 3 The position sensor 19 and the like for reducing the wear of the sensor.

  In the spool 3, annular grooves 4 to 6 are formed, and a high-pressure passage 9 connected to a hydraulic pump, a tank passage 10 connected to a hydraulic tank, and passages 11 and 12 are formed around the groove. An operation check valve 13 is provided between the passage 11 and the cylinder port 2, and the cylinder port 2 and the passage 11 are opened and closed by opening and closing the poppet 13a. The poppet back pressure chamber 13 b of the operation check valve 13 is connected to an electromagnetic solenoid valve 16 through a passage 15.

  In the present invention, the emergency valve 17 is juxtaposed with the electromagnetic solenoid valve 16 at the upper right end portion of the valve body 1 in the drawing, and the bracket 18 is fixed to the right end surface of the valve body perpendicular to the spool 3 shaft with a bolt 18a. A position sensor 19 is fixed to the bracket 18 with bolts 19a. This fluid control valve is mounted on the forklift truck in a state where multiple connections are made with the right side of the drawing as the upper surface, the drive end of the spool 3 is disposed on the upper surface side, and the operation surface of the emergency valve 17 is disposed on the side surface side. Therefore, the emergency valve 17 can be operated without interfering with the position sensor 19 and the bracket 18 of the spool 3. If the operation of the lifting device becomes impossible due to the electromagnetic solenoid valve 16 not working, etc., the emergency valve arranged as in the present invention can be easily operated in an emergency, and can be lifted safely and reliably. The device can be lowered.

  In order to raise the lift with this fluid control valve, the spool 3 is moved to the right from the drawing position (neutral position). When the annular groove 4 moves to the right, the high-pressure passage 9 and the passage 11 communicate with each other, and a high-pressure hydraulic pressure is applied from the passage 11 to the poppet 13a. When the poppet 13a moves upward in the drawing, the passage 11 passes through the passage 11. Pressure oil is supplied to the cylinder port 2. As a result, pressure oil is supplied to the bottom chamber C1 of the lift cylinder C, and the lift rises. When the spool 3 is returned to the neutral position in this state, the passage 11 and the high-pressure passage 9 are blocked and the passage 15 is also closed, so that the lift cylinder C maintains that state. The position sensor 19 senses this state, turns off the battery, stops the electric pump, and prevents the battery from being consumed.

  On the other hand, in order to lower the lift, the spool 3 is moved to the left and at the same time the electromagnetic solenoid valve 16 is energized and opened. As a result, the passage 15 and the passage 12 communicate with each other, and the passage 12 further communicates with the tank passage 10 via the annular groove 5 of the spool 3. That is, the poppet back pressure chamber 13 b of the operation check valve 13 communicates with the tank passage 10. When the passage 15 communicates with the tank passage 10, the pressure in the poppet back pressure chamber 13 b of the operation check valve 13 decreases. On the other hand, in the bottom chamber C1 of the lift cylinder C, the pressure due to the load W and the weight of the piston C2 acts on the lower part of the poppet 13a via the cylinder port 2. That is, the high pressure from the cylinder port 2 acts on the poppet 13a upward in the drawing. At this time, since the poppet back pressure chamber 13b communicates with the tank passage 10, the poppet 13a moves upward to open, and the pressure oil in the bottom chamber C1 of the lift cylinder C flows into the tank passage 10. The lift cylinder C is lowered. The position sensor 19 for detecting the position of the spool is not limited to the contact type as shown in the figure, but can be a sensor that uses the spool 3 as a magnetic body and detects the displacement of the magnetic body with the magnetic sensor.

  The fluid control valve of the present invention is used for industrial vehicles, lift devices, forklifts and the like.

It is side surface sectional drawing (A) and rear view (B) which show the structure of the fluid control valve by the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve body 2 Cylinder port 3 Spool 4 Annular groove 5 Annular groove 6 Annular groove 7 Sleeve 9 High pressure passage 10 Tank passage 11 Passage 12 Passage 13 Operate check valve 13a Poppet 13b Poppet back pressure chamber 15 Passage 16 Electromagnetic solenoid valve 17 Emergency valve 18 Bracket 18a Bolt 19 Position sensor 19a Bolt C Lift cylinder C1 Bottom chamber C2 Piston W Load

Claims (1)

A suction port for sucking high-pressure hydraulic fluid, a discharge port for discharging hydraulic fluid to the hydraulic fluid tank, a sleeve to which a cylinder port for sending high-pressure hydraulic fluid to the lift device is connected, and a flow path between the cylinder port and the discharge port. An electromagnetic solenoid valve that opens and closes, and a valve body that includes an emergency valve that forcibly communicates the cylinder port with the discharge port in the event of a failure of the electromagnetic solenoid valve; In a fluid control valve having a spool having a switching portion for forming a hydraulic fluid flow path and a switching portion for forming a hydraulic fluid flow path by communicating a cylinder port and a discharge port, the emergency valve includes the In parallel with the electromagnetic solenoid valve, the valve body end surface orthogonal to the spool shaft is attached to the spool via a bracket. Fluid control valve, characterized in that by arranging a position sensor for sensing the location.

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