JPS60109679A - Solenoid valve - Google Patents

Abstract

PURPOSE:To detect the movement of a member reliably and quickly by disposing a sensor on the side in the member adapted to displace forward and backward along the axis of a spool or the like. CONSTITUTION:When a spool 11 is not yet moved by a movable iron core 31, light emitted from a projecting element 42a in a sensor body 42 is reflected on a reflection portion 25a to be received by a photo detecting element 42b. Therefore, a signal for indicating that the spool 11 is not yet moved is output. When the movable iron core 31 is operated to move a push rod 25 and the spool 11 to each designated position, light is kept from reflecting toward the photo detecting element 42b by a non-reflection portion 25b of the push rod 25. Therefore, a signal for indicating that the spool 11 has been moved is output.

Description

[Detailed description of the invention]

This invention relates to a solenoid valve. The object of the present invention is to help solve the conventional drawbacks described later, and to accurately and quickly detect the movement of a member moving back and forth in the axial direction of the spool of the valve body from the side. The purpose of this invention is to provide a solenoid valve that can perform the following functions. 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. Inside the base body 4, a space 5 for advancing and retracting the spool and an oil passage 6 are formed. Also, the base body 4 has a hydraulic power source (
For example, port 7 for connecting a cylinder 1), port 8 for connecting an oil tank, port 8 for connecting a driven device such as a hydraulic cylinder 9, 10
These boats communicate with the space 5 or the oil passage 6 for advancing and retreating the spool. A well-known spool 11 is provided in the space 5 for advancing and retracting the spool, and is movable in the left and right directions in FIG. Spring seats are attached to both left and right ends of the spool 11, and spool return springs 13 are interposed between these spring seats ν 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. 1, and each is a compression spring. Next, the solenoid 2 will be explained. This solenoid consists of a driving body 16 for mechanically operating the valve body 1, and a cylindrical excitation body 17 that prevents magnetic force from being applied to the driving body 16. First, the drive body 16 has a fixed core head, and a through hole is bored in the shaft core thereof, and the bushing rod 5 is inserted therethrough so as to be freely movable in the left and right direction as shown in FIG. . One end of the cylindrical member is placed over the other end of the fixed core head, and the two are fixed to each other by welding means so that the space inside the cylindrical member is sealed. The cylindrical member is formed with non-magnetic side slants, and a space for advancing and retracting the movable iron core is formed inside the cylindrical member. A closing member d is fixed to the other end of the cylindrical body by welding means so that the inside is hermetically sealed. A part of the closure body I is provided with a row of through holes, in which a manually operated bushing pin 4 is provided to freely move to the left in FIG. 1 and return to the state shown. . The seal between the through hole Z and Butshubin 4 is an O-ring. A movable iron core 31 is provided in the space formed inside the cylindrical member so as to be freely movable in the left and right directions in FIG. A groove for oil circulation is formed in a part of the surface of the movable core 31 over the entire length in the longitudinal direction, and the oil flows between the left and right sides of the movable core 31 in FIG. It is now possible to move through it. Incidentally, the driving body 16 is also called a tube assembly. Next, the excitation body 17 will be explained. The wings represent the housing, the force represents the coil, and the part represents the yoke. It is formed by molding a synthetic resin material with the coil and yoke embedded in the housing. These may be constructed by housing the coil and yoke portions inside a hollow housing as usual. The fin is a plug pin fixed to the housing wing, and the coil-like lead wire is connected to it. Next, the threaded part provided at the base of the fixing tool is screwed into the threaded part of the closure body η. The first part is an annular holding part that holds down the housing of the exciter 17. Next, the chrysanthemum is a fixing frame, which is made of a hard material (metal or hard synthetic resin) and is fixed to the base body 4 by a fixing tool 40a. Next 4
1 indicates a sensor designed to detect movement of the bushing rod 5. In this figure, C is the sensor body, which includes a light emitting element 42a (light emitting diode) and a light receiving element 42b (7-t
A composite element (referred to as a photointerlager) is used. Numerals 4 and 44 are transparent rods inserted through the fixed core head and the fixed frame frame, and are generally made of a transparent synthetic resin material. Sato is a presser,
It is fixed to the fixed frame 40 with a stopper 45a. This retainer is used to prevent the transparent rod 44 from being pushed out by the pressure of oil within the valve body. The chrysanthemum indicates an O-ring for sealing. Next, the terminal box 3 will be explained. ω is a case made of an insulating material, such as a synthetic resin material,

[E] Fix to the base 4 of the valve body 1 using a different item. Also, inside it is provided with control circuit components such as connection terminals for connecting electric wires for power supply, rectifier circuits, and display circuits. The control circuit component has a well-known socket, to which the plug is removably connected. This is a wire outlet formed in a part of the case group, and is used to pull out the wires connected to the terminal group mentioned above. In the above configuration, when power is supplied to the connecting terminal via an electric wire drawn in from the outside, the power is sent to the coil via the control circuit and the plug. When power is supplied as described above and current flows through the coil, the yoke A, the movable core 31. Magnetic flux passes through a magnetic circuit consisting of a fixed core head. As a result, the movable core 31 is attracted toward the fixed core head and moves in that direction. This movement of the movable iron core 31 is carried out via the bushing rod 3 on the spool 11.
, and the spool 11 moves to the left in FIG. As a result, boats 7 and 9 communicate with each other, and boats 10 and 8 communicate with each other. As described above, the movable iron core 31 operates and the bushing rod 6
The sensor 41 detects that the spool 11 has moved. In other words, the movable iron core 31 and the spool 1 are still
1 is not moved, as shown in FIG. 2, the light emitted from the light emitting element 42a in the sensor body C passes through the transparent rod 5 and is reflected by the reflecting portion 25a of the bushing rod δ. Once again, the transparent light passes through 44 to the light receiving element 42! You can receive it at As a result, the light receiving element 42b outputs a signal indicating that the bush rod 5 has not yet moved, that is, the spool 11 has not yet been moved.Meanwhile, the movable iron core 31 operates to move the bush rod 5 and spool 11 to a predetermined position. In that case, as shown in FIG.
5b, that is, a portion in which a groove is formed around the fish rod 5 and a black paint is applied thereto to prevent light reflection, faces the light-transmitting rod 43. Therefore, as described above, the light emitted from the light projecting element 42a is not reflected toward the light receiving element 42b. Therefore, the light receiving element 42b outputs a signal indicating that the bushing rod 4 has moved and the spool 11 has been moved. Next, when the electricity is turned off as described above, magnetic flux is no longer generated by each coil. Therefore, the movable core 31 is no longer attracted to the fixed core. Then, due to the biasing force of the spool return spring provided on the left side of the spool 11 in FIG. 1, the syspool 11 returns to the neutral position as shown in FIG. Furthermore, the movement of the spool 11 returns the movable iron core 31 to its original position via the dash rod. In this case, as shown in FIG. 2, the reflecting part 5a is again in a state facing the light-transmitting bar, and the light emitted from the light projecting element 42a is reflected by the reflecting part 25a and reaches the light receiving element 42b. do. As a result, the light receiving element 42b outputs a signal indicating that the bushing rod 6 has returned to its original position, that is, that the spool 11 has returned to its original position.Next, the assembly of the above-mentioned solenoid valve will be explained. First, as is well known, the terminal box 3 is attached to the valve body 1. Next, install solenoid 2. For this installation, first fit the fixing frame to the outer circumferential side of the fixed core in the tube assembly. After that, the fixed iron core and the fixed frame are attached to the end face of the base 4 of the valve body 1, and the frame is fixed to the base 4 using the fixing tool 401L. In this case, it goes without saying that the fixed iron core and the fixed frame should be positioned so that the transparent rods 6, 44 and the sensor body C 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, the fixed frame, and the base body 4. When the fixing frame cutter is fixed to the base body 4 in the above manner, the collar portion 2 of the movable core is pressed by the fixing frame, and the driving body 16 and the fixing frame lead 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 part should be inserted into the socket. Next, the fixture group is screwed onto the drive body 16, and the fixture d is tightened so that the holding device at its tip presses the excitation body 17 toward the valve body 1. 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 into a 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 diagonally reflected and does not return toward the light receiving element. It is composed of: It should be noted that parts that are considered to have the same or equivalent structure as those in the previous figure in terms of function are given the same reference numerals as in the previous figure with the letter e, and redundant explanations are omitted. (In addition, the same idea will be used in the next and subsequent ones, and the alphabetical letters "flg" will be added in order to omit duplicate explanations.) Next, Fig. 6 shows an example of a different arrangement position of the sensor. 41f is provided in a through hole bored in the side surface of the base 4f in the valve body. In such a device, the spool 11f has not yet moved and its narrow diameter portion 11b is connected to the sensor body 42f.
When the light emitting element of the sensor is in a position facing the sensor, the light emitted from the light emitting element of the sensor is not reflected toward the light receiving element due to the influence of oil between the sensor and the narrow diameter part 11b.
On the other hand, when the stem 11f moves and the optical diameter section 11a comes to a position facing the sensor, the light emitted from the light projecting element is reflected by the diameter section 11a and goes 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 side position opposite to the end surface of the movable iron 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, Figure 2 shows a further different embodiment of the present invention, in which a light emitting element 42ah in the sensor is provided separately, and these elements and a bushing rod 25h are connected by a translucent rod 56, respectively. This is an example. 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 bushing rod 25i with the same structure as the example in FIG. 1. be. In this example, the bushing rod 251 has a deep groove W formed therein. In such a configuration, the butsch rod 25
If the amount has not moved yet, use Butsch Rod 25i.
Since the peripheral surface of the magnetic sensor 42i is close to the magnetic sensor 42i, the sensor 42i outputs a corresponding signal. On the other hand, rod 2
When 5i moves and deep groove J faces sensor 421,
Since the distance between the bottom of the deep groove and the sensor 42 gate becomes long, the sensor 42i outputs a corresponding signal. As a result, the rod 25 receives the output signal from the sensor 42i.
It is possible to detect whether i has moved. 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 a bushing rod and a movable iron core that move forward and backward in a solenoid are referred to as movable bodies, and members such as the movable body and spool that move forward and backward in a solenoid valve 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. Various other well-known physical changes may be used as this physical change. As described above, in the present invention, when attempting to control fluid by moving the spool U in the valve body 1 back and forth,
By controlling the movable body of the solenoid to move forward and backward, the spool can be driven as is generally known, thereby providing the advantage of being able to switch valves and control fluid. In addition, a sensor d is provided on the side of the reciprocating member such as the spool 11 or a movable body, and the sensor 41 is designed to emit a signal corresponding to the displacement of the retracting member. 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. A further excellent feature of the present invention is that a sensor is provided on the side of the advancing/retracting member. In other words, in conventional detection of this type of advancing/retracting member, the movement of the advancing/retracting member was detected by disposing a detection member in the axial direction. One side of the sensor is blocked by the detection member and its use is restricted (it is impossible to install another solenoid for reciprocating the spool), or the solenoid If a detection member is provided at one end of the movable body of the solenoid valve, the oil pressure must be carefully balanced in consideration of the presence of the detection member in the case of a solenoid valve in which the oil flowing into the valve body flows into the solenoid. However, in the present invention, the sensor is provided on the side of the advancing/retracting member, so the structure becomes complicated, and depending on the poem, malfunction may occur due to changes in hydraulic pressure. There is no such trouble, and it has the revolutionary feature of being able to accurately detect the displacement of the advancing/retracting member.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 1 is a longitudinal sectional view of the solenoid valve, FIG. 2 is a partially enlarged view showing the relationship between the sensor and the bushing rod, and FIG. 3 is a diagram showing the bushing rod in a moved state. , Fig. y is a sectional view taken along the line IV-■, Fig. 3 is a view similar to Fig. 3 showing a different example, and Figs. 6 and 7 are views showing different examples of the arrangement positions of the sensors ( Figure 6 is a horizontal sectional view taken along line VI-Vl in Figure 1)
, 1 and 9 are partial views showing different examples of the sensor, respectively. 1... Valve body, 2... Solenoid, ■... Spool, 31... Movable core, d... Sensor Figure 1 Figure 2 Figure 4 Figure 5 GvJ Figure 7

Claims (1)

[Claims] A valve body that switches fluid by moving a spool provided inside in a minute direction, and a movable body that is attached to the surface of the spool in the axial direction with respect to the body and is installed inside the valve body. and a solenoid capable of driving the spool forward and backward by moving the solenoid forward and backward in the axial direction of the spool, a member that moves forward and backward in the axial direction of the spool or movable body. A sensor for detecting physical changes on the surface of the reciprocating member is disposed on the side of the retractable member, and a portion of the retractable member that faces the sensor is arranged to detect physical changes in the surface of the retractable member. A portion facing the sensor during forward movement and a portion facing the sensor during backward movement are made to have different characteristics so that the displacement signal of the forward/backward movement member is transmitted from the sensor in response to the movement of the forward/backward movement member. A solenoid valve characterized by being capable of transmitting a signal promptly.