JPH0470514B2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a solenoid valve.

Conventionally, an annular distortion plate is placed at the rear end of a reciprocating member such as a spool so that the reciprocating member passes through it, and a spring is interposed between the reciprocating member and the distortion plate to measure the amount of movement of the reciprocating member. Such a configuration is known (see, for example, Japanese Utility Model Application Publication No. 72974/1983).

However, according to the above configuration, the installation location of the distortion plate is limited to the rear end of the reciprocating member, and there is a problem that it is difficult to install it in other locations. For this reason, many types of solenoid valves have drawbacks that make them difficult to use.

In addition, since the advancing/retracting member and the distortion plate are mechanically connected by a spring, an unnecessary load is applied to the advancing/retracting member, which slows down its operation and reduces control accuracy.

In order to solve the above problems, the present invention provides a valve body in which a spool provided inside switches the fluid by moving forward and backward in the axial direction, and a valve body that switches the fluid by moving a spool provided inside the valve body in the axial direction. an electromagnetic solenoid that is attached to the direction side surface and that is capable of driving the spool forward and backward by moving a movable body installed inside the spool forward and backward in the axial direction of the spool; In the valve, on the radial side of the axis of a member such as the spool or the movable body that moves forward and backward in the direction of the axis, a change in the light reception state or a magnetic change on the surface of the forward and backward movement member is detected. A sensor is disposed, and a portion of the advancing/retracting member facing the sensor faces the sensor when moving forward so that a change in the light reception state or a magnetic change can be given to the sensor by moving the member back and forth. To provide a structure in which the characteristics of a part that moves forward and backward are made different from a part that faces the sensor when retracting, so that a displacement signal of the advancing and retracting member can be promptly transmitted from the sensor in response to the advance and retreat of the advancing and retracting member. To provide a solenoid valve that can be used with many types of solenoid valves and that can notify the movement of a retractable member without applying unnecessary load to the retractable member. It is.

The drawings showing the embodiments of the present application will be described below. The solenoid valve has a valve body 1, a solenoid 2 for operating the valve body, and a terminal box 3 for connecting an electric wire for supplying power to the solenoid 2. First, the valve body 1 will be explained. A space 5 and an oil passage 6 for advancing and retracting the spool are formed inside the base body 4. The base body 4 also has a port 7 for connecting a hydraulic source (for example, a pump), a port 8 for connecting to an oil tank, a port 9 for connecting to a driven device, for example, a hydraulic cylinder.
10, and these ports communicate with the space 5 for advancing and retreating the spool or the oil passage 6.
A well-known spool 11 is provided in the space 5 for advancing and retracting the spool.
In FIG. 1, it is freely movable in the left and right directions. Spring seats 12 are attached to the left and right ends of the spool 11, respectively, and spool return springs 13 are interposed between the spring seats 12 and a fixed core of a solenoid, which will be described later. These spool return springs 13 are for positioning the spool 11 in a neutral position as shown in FIG.
A compression spring is used in each case. Next, the solenoid 2 will be explained. This solenoid is the valve body 1
It consists of a driving body 16 for mechanically operating the motor, and a cylindrical excitation body 17 for exerting a magnetic force on the driving body 16. First, the driving body 16 is the fixed iron core 2
0, and a through hole 24 is bored in its axial center, into which a bushing rod 25 is inserted so as to be freely movable in the left and right direction in FIG. One end of a cylindrical body 26 is placed over the other end of the fixed iron core 20, and both are fixed to each other by welding means so that the space inside the cylindrical body is sealed. The cylindrical body 26 is made of a non-magnetic material, and has a space formed therein for moving the movable core forward and backward. A closing body 27 is fixed to the other end of the cylindrical body 26 by welding means so that the inside thereof is sealed. A through hole 28 is provided in a part of the closure body 27, and a push pin 29 for manual operation is provided therein so that it can be freely moved to the left in FIG. 1 and returned to the state shown in the figure. . The seal between the through hole 28 and the push pin 29 is provided by an O-ring 30. A movable iron core 31 is provided in a space formed inside the cylindrical body 26 so as to be movable in the left and right directions in FIG. A groove 32 for oil circulation is formed in a part of the circumferential surface of the movable core 31 over its entire length in the longitudinal direction, so that oil flows between the left and right sides of the movable core 31 in FIG. It is adapted to be able to move through the groove 32. The drive body 16 is also called a tube assembly. Next, the excitation body 17 will be explained. 33 is a housing, 34 is a coil, and 35 is a yoke. The housing 33 is formed by molding a synthetic resin material with the coil 34 and yoke 35 embedded therein. These may be constructed by housing the coil 34 and yoke 35 inside a hollow housing as usual. 36
is a plug pin fixed to the housing 33, to which the lead wire of the coil 34 is connected. Next 3
Reference numeral 7 denotes a fixture, and a threaded portion provided at its base portion 38 is screwed into the threaded portion of the closure body 27. 3
Reference numeral 9 denotes an annular holding portion that holds the housing 3 of the excitation body 17.
It is designed to suppress 3. Next, 40 is a fixed frame made of hard material (metal or hard synthetic resin)
It is fixed to the base body 4 by a fixing member 40a. Next, reference numeral 41 indicates a sensor adapted to detect movement of the push rod 25. In the sensor body 42, a composite element (referred to as a photointerrupter) including a light emitting element 42a (light emitting diode) and a light receiving element 42b (phototransistor) is used. Numerals 43 and 44 are transparent rods inserted through the fixed core 20 and fixed frame 40, and are generally made of transparent synthetic resin material. 45 is a presser, and the stop 45
It is fixed to the fixed frame 40 with a point a. This holding member 45 is used to prevent the transparent rods 43 and 44 from being pushed out by the pressure of oil within the valve body. 46 indicates an O-ring for sealing. Next, the terminal box 3 will be explained. 50
is a case made of an insulating material, such as a synthetic resin material, and is fixed to the base 4 of the valve body 1 using a stopper 51. Further, inside thereof, a connection terminal 52 to which a power supply wire is connected, and a control circuit 53 such as a rectifier circuit or a display circuit are provided. The control circuit 53 has a well-known socket to which the plug 36 is removably connected. Reference numeral 54 denotes an electric wire outlet formed in a part of the case 50, and is used to draw out the electric wire connected to the terminal 52.

In the case of the above configuration, when power is supplied to the connection terminal 52 via the electric wire drawn in from the outside, the power is passed through the control circuit 53 and further to the plug 3.
6 to the coil 34. When power is supplied and current flows through the coil 34 as described above, magnetic flux passes through the magnetic circuit consisting of the yoke 35, the movable iron core 31, and the fixed iron core 20. As a result, the movable iron core 31
is attracted toward the fixed iron core 20 and moves in that direction. This movement of the movable iron core 31 is transmitted to the spool 11 via the push rod 25, and the spool 11 moves to the left in FIG. As a result, port 7 and port 9 communicate with each other, and port 10 and port 8 communicate with each other.

The sensor 41 detects that the movable iron core 31 is operated and the push rod 25 and the spool 11 are moved as described above. That is, when the spool 11 is not yet moved by the movable iron core 31, the sensor body 42 is moved as shown in FIG.
The light emitted from the light projecting element 42a passes through the light transmitting rods 44, 43, is reflected by the reflecting portion 25a of the push rod 25, passes through the light transmitting rods 43, 44 again, and is received by the light receiving element 42b. As a result, the light receiving element 42b outputs a signal indicating that the push rod 25 has not yet moved, that is, the spool 11 has not yet been moved.

On the other hand, the movable iron core 31 operates and the push rod 2
5 and the spool 11 move to a predetermined position, in that case, as shown in FIG. 3, a non-reflective portion 25b of the push rod 25, that is, a groove is formed around the push rod 25 to prevent light from being reflected there. The part on which the black paint is applied faces the transparent rod 43. Therefore, as described above, the light emitted from the light emitting element 42a is transmitted to the light receiving element 42b.
Do not reflect towards. Therefore, the light receiving element 42b outputs a signal indicating that the push rod 25 has moved and the spool 11 has been moved.

Next, when the above-described current supply is cut off, the coil 34 no longer generates magnetic flux. Therefore, the movable iron core 31
is no longer attracted to the fixed iron core 20. Then the first
The spool 11 is returned to the neutral position as shown in FIG. 1 by the biasing force of a spool return spring 13 provided on the left side of the spool 11 in the figure. Further, the movement of the spool 11 causes the movable iron core 31 to be returned to its original position via the push rod 25.

In this case, as shown in FIG. 2, the reflecting section 25a is again in a state facing the light transmitting rod 43, and the light emitted from the light projecting element 42a is reflected by the reflecting section 25a and reaches the light receiving element 42b. As a result, the light receiving element 42b outputs a signal indicating that the push rod 25 has returned to its original position, that is, that the spool 11 has returned to its original position.

Next, the assembly of the above electromagnetic valve will be explained. First, as is well known, the terminal box 3 is attached to the valve body 1.
Next, install solenoid 2. This installation begins with the fixed core 20 in the tube assembly 16.
A fixing frame 40 is fitted on the outer peripheral side of the. After that, the fixed iron core 20 and the fixing frame 40 are applied to the end face of the base 4 of the valve body 1, and the frame 40 is fixed to the base 4 using the fixing tool 40a. In this case, it goes without saying that the fixed iron core 20 and the fixing frame 40 are positioned so that the transparent rods 43, 44 and the sensor body 42 are in an overlapping state as shown in FIG. For positioning, it is preferable to provide a fitting portion for positioning on a portion of each of the fixed core 20, fixed frame 40, and base 4. When the fixed frame 40 is fixed to the base body 4 as described above, the flange 21 of the movable core is attached to the fixed frame 4.
0, and the driving body 16 and the fixing frame 40 are fixed to the base body 4. Thereafter, the excitation body 17 is placed on the outside of the drive body 16. In this case, the plug 36 is inserted into the socket. Next, the fixture 37 is screwed onto the drive body 16,
The fixture 37 is tightened so that the presser part 39 at the tip presses the excitation body 17 against the valve body 1 side.
This completes the assembly of the solenoid valve.

Next, FIG. 5 showing a different embodiment of the present application will be described. This figure shows an example in which the structure of the non-reflective portion is different from that described above. In the figure, the non-reflective portion 25be is formed in a V-groove shape as shown in the figure, so that the light emitted from the light emitting element and reaching the non-reflective portion 25be is not diagonally reflected and returned toward the light receiving element. It is configured.

It should be noted that the same reference numerals as those in the previous figure are appended with an alphanumeric letter "e" for parts that are functionally the same or equivalent to those in the previous figure, and redundant explanations are omitted.
(Furthermore, in the following figures, the same concept is applied sequentially, and the alpha alphabets f and g are added in order to omit redundant explanations.) Next, Figure 6 shows an example of a different arrangement position of the sensor. This shows an example in which the sensor 41f is provided in a through hole 55 formed in the side surface of the base 4f in the valve body. In the case of such a device, when the spool 11f is not yet moved and its narrow diameter portion 11b is in a position facing the sensor main body 42f, the light emitted from the light emitting element of the sensor is transmitted to the sensor and the narrow diameter portion. 11b, the light is not reflected toward the light receiving element, and when the spool 11f moves and the large diameter portion 11a comes to a position facing the sensor, the light is not emitted from the light emitting element. The reflected light is reflected by the large diameter portion 11a and directed toward the light receiving element. As a result, the light receiving element in the sensor outputs signals indicating that the spool has not yet moved and that it has moved.

Next, FIG. 7 shows a further different embodiment of the arrangement position of the sensor, and shows an example in which the sensor is provided at a lateral position opposite to the peripheral surface of the end of the movable core on the side opposite to the valve body. . In this example, when the movable core has not yet moved toward the valve body, light from the light emitting element in the sensor is reflected by the movable core, whereas after the movable core has moved, the Since the iron core is not located at a position facing the sensor, the light is not reflected.

Next, FIG. 8 shows a further different embodiment of the present application, in which a light projecting element 42ah in the sensor is provided separately, and these elements and a push rod 25h are provided separately.
This shows an example in which the two are connected by transparent rods 56, 56, respectively.

Next, FIG. 9 shows a further different embodiment of the present invention, in which a magnetic sensor is used as the sensor, and this is arranged near the push rod 25i with the same structure as the example in FIG. 1. be.
In this example, the push rod 25i has a deep groove 5.
7 is formed.

In such a structure, when the push rod 25i is not moving yet, the circumferential surface of the push rod 25i is close to the magnetic sensor 42i, so the sensor 42i outputs a corresponding signal. On the other hand, when the rod 25i moves and the deep groove 57 faces the sensor 42i, the distance between the bottom of the deep groove and the sensor 42i becomes longer, so the sensor 42i outputs a corresponding signal. Thereby, it is possible to detect whether or not the rod 25i has moved using the output signal of the sensor 42i. In the example shown in FIG. 6 or FIG. 7, a magnetic sensor may be used as the sensor.

In this specification, members such as push rods and movable iron cores that move forward and backward in the solenoid are referred to as movable bodies, and members such as the movable body and spools that move forward and backward in solenoid valves are referred to as forward and backward members.

Furthermore, the above-mentioned changes in light reflection and magnetic changes are also referred to as physical changes.

As described above, in the present invention, when attempting to control the fluid by moving the spool 11 in the valve body 1 forward and backward, as is generally known, the movable body of the solenoid is controlled to move forward and backward. It has the advantage of controlling the fluid by driving the spool and switching the valve.

Moreover, a sensor 41 is provided on the side of the reciprocating member such as the spool 11 or a movable body, and the sensor 41 emits a signal corresponding to the displacement of the retracting member, so that the reciprocating member is moved back and forth. It has the advantage of being able to detect valve switching without any time delay and output a signal. This has the advantage that the signal can be used to accurately and reliably link other machine operations.

Particularly, an excellent feature of the present invention is that the radial side of the axis of a member such as a spool or a movable body that moves forward and backward in the direction of the axis, changes in the light reception state or magnetic change on the surface of the forward and backward movement member. A sensor configured to detect the light is disposed, and a portion of the reciprocating member facing the sensor is configured to be able to apply a change in the light reception state or a magnetic change to the sensor by reciprocating the member. At the point. By having such a configuration, it is useful in being able to solve the above-mentioned conventional problems.

To repeat, a sensor capable of detecting a change in the light receiving state or a magnetic change can be installed at any position on the radial side of the axis of the reciprocating member. This can be said to be a highly useful effect that can be applied to many different types of solenoid valves.

In addition, the present invention does not mechanically connect other objects to the advancing/retracting member for measurement, and does not apply a special load, so the spool movement remains light and can be accurately controlled. There is also.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 1 is a longitudinal cross-sectional view of the solenoid valve, FIG. 2 is a partially enlarged view showing the relationship between the sensor and the push rod, and FIG. 3 is a diagram showing the state in which the push rod is moved. , Figure 4 is -
5 is a diagram similar to FIG. 3 showing a different example, and FIGS. 6 and 7 are diagrams showing different examples of sensor placement positions (FIG. 6 is a diagram similar to FIG. 3 in FIG. 1). 8 and 9 are partial views showing different examples of the sensor, respectively. 1... Valve body, 2... Solenoid, 11... Spool, 31... Movable iron core, 41... Sensor.

Claims (1)

[Claims] 1. A valve body in which a spool provided inside switches the fluid by moving back and forth in the axial direction, and a valve body that is attached to the surface of the spool in the axial direction with respect to the main body, and An electromagnetic valve comprising a solenoid capable of moving the spool forward and backward by moving a movable body thereof forward and backward in the axial direction of the spool, wherein the axial center of the spool or the movable body A sensor is disposed on the radial side of the axis of the member that moves forward and backward in the direction, and is arranged to detect a change in the light receiving state or a magnetic change on the surface of the moving member. The opposing parts include a part that faces the sensor when moving forward and a part that faces the sensor when retreating so that the member can change the light receiving state or magnetically change the sensor by moving the member back and forth. The solenoid valve is characterized in that the characteristics of the solenoid valves are different from each other, so that the sensor can promptly transmit a displacement signal of the advancing/retracting member in response to the advancing/retracting movement of the advancing/retracting member.