JPS63285379A - Plunger of oil-immersed solenoid - Google Patents

Abstract

PURPOSE:To provide a solenoid with simple structure, low production cost and light weight by laminating a plurality of punched plates made of magnetic material having an oil path and joining integrally them with a connecting rod to form a plunger. CONSTITUTION:In the lengthwise central portion of a guide tube 1 is inserted axially slidably a plunger 18. The plunger 18 is formed by laminating a plurality of press punched plates 19 made of magnetic material steel plate and having a larger diameter and a lowermost smaller diameter punched plate 24. The larger diameter punched plates 19 are provided in the center with connecting through holes 20 respectively and therearound with three oil passing holes 21 disposed at equal angular intervals. Also, the smaller diameter punched plate 24 is formed in the center with a connecting hole 25 and on the outer periphery with three semicircular oil passing grooves 26. the punched plates 19, 24 are aligned and laminated with each other to be coupled integrally with a connecting rod 28.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a plunger for use in oil-immersed solenoids of the type in which oil flows into a guide tube, such as for driving hydraulic valves.

Problems to be Solved by the Prior Art and the Invention The plunger of an oil-immersed solenoid needs to have an oil passage hole or an oil passage groove extending from one end to the other end in order to circulate oil in the tube during operation. However, after turning, a drilling or grooving process must be added, resulting in higher processing costs than a dry type solenoid plunger.

Means for Solving the Problems As a means for solving these problems, the plunger of the present invention has a connecting hole in the center and an oil passage hole in the eccentric part, or , multiple punched plates made of magnetic material with oil grooves extending from one side to the other on the outer periphery.
The connecting hole and the oil passage hole or oil passage groove are stacked in alignment with each other, and are integrally connected by a connecting rod passing through the connecting hole.

Functions and Effects of the Invention The plunger of the present invention has the above-mentioned structure, and can be processed by a press with extremely high production efficiency.By stacking and integrally connecting four punched plates, an oil passage hole or an oil passage groove can be formed. Since it can be manufactured without performing cutting work, which has low production efficiency, it has the effect of significantly reducing manufacturing costs.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

In the figure, l is a guide tube made of a non-magnetic material such as phosphor bronze or non-magnetic stainless steel, and the upper end is formed with an arc-shaped abutment 2 and an opening 3, and the lower end is formed with an abutment 2 and an opening 3. Tsuba 4 is curved. In addition, this guide tube 1 may be made non-magnetic only at the middle part in the length direction, and both upper and lower sides may be formed from a magnetic material.

An insulating film 6 made of an insulating material such as synthetic resin is wrapped around the outer periphery of the guide tube l above the bottom plate 5 applied to the upper surface of the collar 4, excluding the upper end portion, and a coil 7 is wound around it. A steel outer cylinder 8 is attached around it, and a reduced diameter part 9 formed by constricting and bending the upper end is tightly fitted to the guide tube l, and the outer cylinder 8 is made of steel and is passed through a collar 10 formed by bending the lower end. It is fastened to the bottom plate 5 by bolts 11.

A steel core 12 is tightly fitted into the lower part of the guide tube 1. A center hole 13 is formed through the core I2, and a large diameter hole is formed in the upper surface. 4 and the small diameter hole 15 are the center hole 13
A housing hole 16 and a flange I7 are formed on the lower surface.As shown in Fig. 3, the flange I7 is made by turning the hem of a cylindrical rough material turned from a round bar. It is formed by bending it outward at right angles using high spin processing.

A plunger 18 is fitted into the longitudinal center of the guide tube l so as to be able to slide freely in the axial direction, and the plunger 18 is made of a large number of large-diameter punching plates 19 formed by stamping a steel plate using a press. and one small-diameter punching plate 24 on the bottom layer, and the large-diameter punching plate 19 is arranged around a connecting hole 20 made transparent in the center, as shown in FIG. Three oil holes 21 are provided at regular intervals, and the upper surface is pressed between each oil hole 21 to form a recess 22 on the upper surface and a convex portion 23 on the lower surface. In addition, the small-diameter punched plate 24 has a connecting hole 25 in the center, three semicircular oil grooves 26 on the outer periphery, and four semicircular parts 27 on the outer periphery of the upper surface. A large number of large-diameter punching plates I9 and one small-diameter punching plate 24 are aligned so that the connecting holes 20.25 are aligned, and the convex portions 23 of the upper layer are connected to the four portions 22.27 of the lower layer. In addition, each oil passage hole 21 and oil passage groove 2
6 are aligned and laminated, and a connecting rod 28 made of a non-magnetic material such as phosphor bronze or non-magnetic stainless steel and having an enlarged diameter portion 29 formed in the center in the length direction is connected to the connecting hole 20.25.
The small-diameter punching plate 24 of the lowermost layer is applied to the upper end of the enlarged diameter part 29, and the part protruding from the upper surface of the large-diameter punching plate 19 of the uppermost layer is crushed to form the retaining part 28b. The concave portions 22.27 and convex portions 23 of each punched plate 19.24 are fitted together to extend the oil passage holes 21 and oil passage grooves 26 from the upper surface to the lower surface. At the same time as the upper end of the connecting rod 28 is crushed to form the retaining portion 28b, or in a separate process, the stacked punched plates 19 and 24 are strongly pressed in the stacking direction. As a result, the convex portion 23 is formed within the concave portion 22.27.
are press-fitted and connected, and serve to prevent a decrease in magnetic permeability due to gaps between the joining surfaces of each punched plate 19.24. In this plunger 18,
The small-diameter punching plate 24 in the lowermost layer has a large-diameter hole 14 in the core 12.
By fitting into the core 12, the plunger 18 is inserted into the core 12.
This is to maintain a strong suction force above a certain value in a certain stroke range close to the connecting rod 28.
The enlarged diameter portion 29 has a lower end surface that is connected to the small diameter hole I5 of the core 12.
between the lower surface of the small diameter punching plate 24 and the bottom surface 14a of the large diameter portion 14 of the core 12, and between the lower surface of the lowermost large diameter punching plate 19 and the top of the core 12. A gap is created between each plunger 18 and the end face.
The lower part of the connecting rod 28 is connected to the center hole 1 of the core 12, and the lower part of the connecting rod 28 is connected to the center hole 1 of the core 12.
A bushing pin 28a penetrates through 3 and projects downward.

Guide tube! A movable stopper 30 made of synthetic resin with an O-ring 32 fitted on the outer periphery is fitted tightly and slidably in the axial direction in the upper part of the inside, and the circular arc portion of the outer periphery of the upper surface is connected to the guide tube. The protrusion 31 at the center of the upper surface is exposed to the outside through the opening 3.

The solenoid having the above structure is fastened to the body a of the hydraulic valve by bolts 33 passed through the collar 10 of the outer cylinder 8 and the bottom plate 5, and the stem C is slidably inserted into the sliding hole of the body. It is pushed up toward the solenoid by the elasticity of a return spring (not shown), and its upper end abuts against the lower end of the bushing pin 28a at the lower part of the connecting rod 28 of the plunger 18. A coil spring 36 installed between them prevents them from floating. Note that an O-ring 35 is provided between the body a of the hydraulic valve and the end face of the core 12, and an O-ring 34 is provided between the core 12 and the guide tube.
In each case, the sealed oil is prevented from leaking.

Next, the operation of this embodiment will be explained.

The oil flowing out from between the sliding hole of the hydraulic valve and the stem C flows into the guide tube 1 through between the center hole 13 of the core 12 and the bushing pin 28a, and the current to the coil 7 is cut off. In this state, as shown by the chain line in FIG. 1, the stem C is pushed up by the elasticity of a return spring (not shown), and the plunger 18 is pushed up and separated from the core 12 and hits the movable stopper 30 upward. position and when coil 7 is energized, core 12
Then, the plunger 18 is energized, the plunger 18 is drawn toward the core 12, and the enlarged diameter portion 29 of the connecting rod 28, which acts as an electromagnetic killer, moves toward the core 12, as shown by the solid line in FIG.
2 small diameter holes! The plunger stops at the position where it hits the bottom surface 15a of the plunger C, and pushes down the stem C against the elasticity of a return spring (not shown). 8, the oil in the guide tube l flows to the other side through the oil passage groove 26 and the oil passage hole 21.

To manually push down the stem C while the coil 7 is de-energized, as shown in Figure 4,
When a rod is inserted into the opening 3 at the upper end of the guide tube l and the protrusion 31 of the movable stopper 30 is pushed, the movable stopper 3
0 slides downward, and the stem C is pushed down together with the plunger 18.

As mentioned above, the plunger 1 of the solenoid of this embodiment
8 is a stack of punched plates 19 and 24 punched and formed by a press and integrally connected by a connecting rod 28, so the processing cost is significantly reduced compared to conventional products manufactured by cutting. .

Note that the connecting rod 28 may be separated from the enlarged diameter portion 29 serving as an electromagnetic killer and the bushing pin 28a below it and made into a separate body, and in this case, the connecting rod 28 may be made of a magnetic material. Further, only the bushing pin 28+1 may be separated from the portion above the enlarged diameter portion 29 which serves as an electromagnetic killer, and may be made into a separate body.

Also, plunger! A large number of large-diameter punching plates 1 constitute 8.
By using steel plate 9 with excellent workability and using electromagnetic soft iron with high magnetic permeability for the small-diameter punched plate 24 at the lowermost stage, the attractive force characteristics can be improved without increasing the manufacturing cost.

The advantages of this embodiment other than the above are listed below.

(1) Conventionally, the stopper at the upper end of the guide tube was made of metal, welded to the guide tube, and had a manual operation bushing pin fitted in the center of the stopper, resulting in a complex structure and cost. However, in this embodiment, the upper end of the guide tube l is narrowed into an arc shape to form the abutting part 2, and a synthetic resin bushing pin is attached to this. Movable stopper 30
Since the structure is simple, the cost is reduced, the weight can be reduced, the number of parts is small, and failures are less likely to occur.

(2) Conventionally, in order to increase magnetic efficiency by increasing the area of the surface of the upper end of the outer cylinder that is the external fixed iron core facing the guide tube, that is, the magnetic path area, and increasing the magnetic efficiency, a ring was placed between the upper end of the outer cylinder and the coil. However, in this embodiment, this is abolished, and a reduced diameter part 9 that protrudes upward is curved at the center of the upper end of the outer cylinder, and its inner peripheral surface is attached to the guide tube 1. Since the magnetic path area is ensured by fitting and facing the plunger 18, the number of parts is reduced, making it possible to reduce weight and cost. There is an advantage that the output can be improved by increasing the number of turns, or the outer cylinder can be made smaller to make it more compact.

(3) Conventionally, solenoid coils were wound around a bobbin and fitted into a guide tube. Since the coil 7 is wound on top, it is possible to reduce weight and cost, and
You can improve the output by increasing the number of turns of the coil by the amount of the bobbin, or you can reduce the size by making the outer cylinder smaller. Furthermore, the amount of heat dissipated from the coil 7 into the guide tube l increases. This has the advantage of preventing overheating.

(4) Conventionally, the core was machined from a round bar to form the flange and male thread for attachment to the valve body, but the male thread was eliminated and the flange was tightened to the body λ of the outer cylinder 8.
7 is clamped and fixed, and the flange 17 is formed by bending, so the material has a small diameter, which has the advantage of reducing material costs and processing costs.

(5) Conventionally, the plunger, which is a magnetic material, and the bushing pin, which is a non-magnetic material, are separate bodies, and the bushing pin only abuts the end face of the plunger, and moves freely within the center hole of the core. In this embodiment, the bushing pin 28a is integrally connected to the plunger 18 and is prevented from floating in the center hole 13 of the core 12. Therefore, core 1
2 has the advantage of low sliding resistance.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is an enlarged partially cutaway perspective view of a punching plate, Fig. 3 is a sectional view showing a method of processing a core, and Fig. 4 is an operation of a movable stopper. FIG. ! = Guide tube 2: Abutment 3: Opening 5: Bottom plate
6: Insulating film 7: Coil 8: Outer cylinder 9: Reduced diameter part 12: Core I8 Niblunger! 9.24: Punching plate 20.25: Connection hole 21: Oil passage hole 26: Oil passage W
It 22.27: Concave portion 23: Convex portion 28: Connecting rod
29: Expanded diameter part (electromagnetic killer) 28a: Push bin 30: Movable stopper Applicant: CKD Controls Co., Ltd. Agent
Patent Attorney Hiroshi Noguchi 20th Houki 3 Son

Claims (1)

[Claims] In the plunger of an oil-immersed solenoid, the plunger of an oil-immersed solenoid slides through the guide tube into which oil flows due to the attraction force with the core, which is excited by energizing a coil wound around the guide tube. A plurality of punched plates made of magnetic material with an oil passage hole formed in the eccentric part or with an oil passage groove extending from one side to the other on the outer periphery are inserted into the connection hole and the oil passage hole. A plunger for an oil-immersed solenoid, characterized in that the holes or the oil passage grooves are stacked in alignment with each other and are integrally connected by a connecting rod penetrating the connecting hole.