JPS6031209A - Proportional solenoid - Google Patents

Abstract

PURPOSE:To reduce the size and the weight of a solenoid by a method wherein a recovering spring of a movable core is formed by a non-linear load characteristics member corresponding to the movable core attracting characteristics of the solenoid and traveling distance of the movable core is made linearly proportional to the applied current. CONSTITUTION:A solenoid 101 is composed of a movable core 101 with a spool valve 3 and a static core 501. Recessed groove 201a, 501a are formed at the center parts of facing ends of the cores 201 and 501 respectively and a conical plane is formed at a peripheral part of the facing ends. A drum spring 9 with non-linear load characteristics is suspended between the recessed grooves 201a and 501a. A solenoid coil 701 is wound between a bobbin 8 and a yoke 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solenoid used, for example, in a solenoid pulp for hydraulic control, and particularly to a proportional solenoid in which the energizing current and the distance traveled by the core are linearly proportional.

Conventionally, there has been one of this type as shown in FIG. 1 (4), ω). In the figure, 1 is a solenoid, and a spray valve 3 is attached to a movable core 2 of the solenoid, which is slidably housed in a valve hole (not shown). 4 is a cylindrical yoke integrally formed with flanges 4a and 4b at both ends; 5 is a fixed iron core that is integrally fixed to the flange 4a and has a conical surface at the end; 6 is a fixed iron core 5; Compression coil springs with equal pitches are stretched between the formed groove 5a and the groove 2a formed at the rear end of the movable iron core 2, and 7 is a pobbin 8 provided on the outer periphery of the fixed iron core 5.
This is a solenoid coil wound in an annular space formed between the inner peripheral surface of the yoke 4 and the inner peripheral surface of the yoke 4.

Note that the contact surface of the movable core 2 with the fixed core 5 is the fixed core 50.
It is formed by a conical surface with the same shape as the conical surface. Further, 2b is a chamfered portion formed at the front end of the movable iron core 2, which is intended to improve device characteristics.

A and B indicate the gap between the iron cores 2 and 5, and C indicates the stroke of the movable iron core 2.

Next, the operation of the above-mentioned conventional device will be explained using FIGS. 2(4) and (6). In FIG. 2(A), the vertical axis shows the suction force generated in the movable core 2 of the solenoid 1, and the horizontal axis shows the amount of movement (stroke) of the movable core (plunger) 2. Characteristic line a
, b, and c respectively indicate the case where a constant current is passed through the solenoid coil 7 (however, the current value gradually increases in the order of a l b l C), and d indicates the case where a constant current is passed through the solenoid coil 7.
2 shows the pressing force acting on the movable iron core 2. The actual operating range is a stroke between gap A and gap B. Further, in FIG. 2 (J3), the vertical axis shows the amount of movement of the movable iron core 2, and the horizontal axis shows the current flowing through the solenoid coil 70 (coil current). Therefore, the characteristic line e indicates the movement position of the movable iron core 2 with respect to the current of the solenoid coil 7 (the equilibrium position of the excitation force of the solenoid coil 7 and the deflection reaction force of the compression coil spring 6). Solenoid 1 is shown in Figure 2 (4
), (B), and the excitation force characteristics of the movable core 2, especially its linearity, are determined by the axial drawn contact position and shape of the fixed core 5 and the movable core 2.

However, in the conventional device described above, a special shape has to be adopted in order to make the excitation force characteristic of the solenoid 1, that is, the attractive force characteristic of the movable core 2, a straight line, and the efficiency of the device is poor. The disadvantage is that the device is large because the suction force is not at its maximum value.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional solenoid, and includes setting the solenoid shape to a shape that maximizes efficiency, and configuring the return spring with a non-linear load characteristic spring that matches this inlay characteristic. The object of the present invention is to provide a proportional solenoid that has maximum suction force, good linearity of operating characteristics, is lightweight, small, and has good control characteristics.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 3, 101 is a solenoid, 201 is a movable core with a spool valve 3, 501 is a fixed core, and core 2
01 and 501 have grooves 201a at the center of the opposing ends, respectively.

501a is formed, and a conical surface is formed around the opposite end, and a suspension spring 9 having nonlinear load characteristics is stretched between the grooves 201a and 501a.

701 is a solenoid coil wound between the pobbin 8 and the yoke 4.

This embodiment is configured as described above.
, 501 is provided at the axial center of the yoke 4, and the conventional chamfered portion 2b is abolished, the suction force characteristics of the solenoid 101 can be improved as shown in FIG. 4 (4). f
, g, and h, the differential coefficient becomes a negative exponential curve. Here, when the return spring is a compression coil spring 6 as in the conventional case (when the amount of deflection and the load are linearly proportional), the operating characteristics of the solenoid are as shown in FIG. 5 (4). That is, the characteristic is non-linear and has hysteresis, as shown by the characteristic line i. On the other hand, when a suspension spring 9 having a load characteristic as shown in the characteristic line m in FIG. 4 (4) is used as the return spring as in this embodiment, the operating characteristic is as shown in FIG. It has a straight portion as shown by line j. In the end, the operating characteristics of the solenoid in this example are as follows:
(in the figure) and has a straight line portion l, so this straight line portion l is used for the operating range from gap A to gap B.

As described above, in the above embodiment, the efficiency of the solenoid (attractive force characteristics with respect to coil current) is large because the solenoid shape is not made into a special shape.

The iron cores 201, 501 and the solenoid coil 701 can be made small, and a light and small solenoid can be obtained. Moreover, by using the stiff spring 9 as the return spring, a device having linear operating characteristics can be obtained.

Although the suspension spring 9 is used as the nonlinear load characteristic spring in the above embodiment, a conical spring, an uneven pitch spring, a bamboo spring, etc. may also be used. Further, although the movable core 2 has the spool valve 3, it may have other components.

As described above, in the present invention, the return spring of the movable core is formed by a member with a nonlinear load characteristic corresponding to the movable core suction characteristic of the solenoid, so that the current flow of the solenoid fill and the moving distance of the movable core are linearly proportional. In addition, it is not necessary to make the core etc. into a special shape in order to provide linearity to the suction characteristics of the movable iron core as in the past, and the suction characteristics can be maximized. Therefore, the iron core, coil, etc. can be downsized, and a lightweight, small, and inexpensive proportional solenoid can be obtained. Further, since the operating characteristics have linear proportionality, good control characteristics can be obtained.

[Brief explanation of the drawing]

Figures 1 (4) and 3) are a sectional view of a conventional proportional solenoid and a front view of a compression coil spring, respectively, and Figure 2 (a). CB) is an attraction force characteristic diagram and an operation characteristic diagram of a conventional proportional solenoid, respectively, FIG. 3 is a sectional view of a proportional solenoid according to the present invention, and FIGS. Attraction force characteristic diagram and operating characteristic diagram, Figure 5 (
4) and ω) are an operating characteristic diagram when a compression coil spring is used as a return spring in the proportional solenoid having the structure of the present invention, and an operating characteristic diagram of the proportional solenoid according to the present invention, respectively. 3... Spool valve, 4... Yoke, 4a, 4b...
Flange part, 9... Tsuzumi spring, 101... Solenoid,
201... Movable iron core, 201a, 501a... Concave groove, 501... Fixed iron core, 701... Solenoid coil. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa Fig. 1 (A) Fig. 2 Fig. 3 Fig. 4 (B) Fig. 15 (A) (B) Ri Koinodo t3 coil power supply

Claims (4)

[Claims] (1) In a proportional solenoid in which a solenoid coil is wound and a movable core is attracted by an excitation force, the return spring that returns the movable core is made of a nonlinear load characteristic member that has nonlinear load characteristics according to the solenoid attraction characteristics. death,
A proportional solenoid characterized in that the energizing current of the solenoid coil and the moving distance of the movable iron core are linearly proportional. (2) The proportional solenoid according to claim 1, wherein the movable core has a valve body slidably housed in the valve hole. (3) A solenoid coil is wound around the inner periphery of a cylindrical yoke having flanges at both ends, and a fixed iron core is disposed in the internal space of the solenoid coil, and the solenoid coil is axially slidable in opposition to the fixed iron core. Claim 1 or 2, characterized in that the movable iron core is disposed so as to be movable, and the contact surface of the fixed iron core and the movable iron core is disposed at the axial center of the yoke. proportional solenoid. (4) Claims 1 to 3, characterized in that the nonlinear load characteristic member is formed of any one of a string spring, a conical spring, an uneven pitch spring, and a bamboo shoot spring. proportional solenoid.