JP2001068334A - Linear solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the centering accuracy of a rod. SOLUTION: In an electromagnet section 2 of a linear solenoid valve having a pressure-adjusting valve section 1 and the section 2, bearings 5 made of a sintered metal for pivotally supporting a stainless rod 4, which performs a pressure-adjusting function while being linearly driven through conduction to a coil 3, have inner circumferential surfaces which are substantially arcuate in cross section, whereby the inner circumferential surface of each bearing 5 comes in substantially circumferential linear contact with the mating outer circumferential surface of the rod 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a linear solenoid valve used in a hydraulic circuit of a hydraulic control device.

[0002]

2. Description of the Related Art In an electromagnet section of a linear solenoid valve having a pressure regulating valve section and an electromagnet section, an inner peripheral surface of a bearing for supporting a rod, which is linearly driven by energizing a coil and used for pressure regulating operation, is provided. The contact with the outer peripheral surface of the rod is a substantially circumferential surface contact. As another means, the inner peripheral surface of the bearing is brought into contact with the outer peripheral surface of the rod via a ball bearing.

[0003]

However, in the former case, there is a limit to the finishing accuracy of the related parts themselves and the accuracy in assembling them, and the contact area between the bearing and the rod is large, so that the sliding friction resistance is extremely increased. In practice, a gap is provided between the bearing and the rod in order to cause the above. For this reason, the centering accuracy of the rod is poor and the pressure regulation characteristics are deteriorated. In the latter case, it is apparent that the productivity is lowered and the cost is increased. Accordingly, it is an object of the present invention to provide a linear solenoid valve which can improve the centering accuracy of a rod at a relatively low cost.

[0004]

Means for solving the problems are as described in the claims.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. However, this is merely an exemplary embodiment adopted based on the present invention, and the present invention will be described based on matters unique to the embodiment. Therefore, the technical scope of the present invention should be determined based on the matters stated in the claims and matters substantially equivalent to the matters.

In the illustrated embodiment, a stainless steel rod 4 linearly driven by energization of a coil 3 and used for pressure control operation is used in an electromagnet section 2 of a linear solenoid valve having a pressure control valve section 1 and an electromagnet section 2. The inner peripheral surface of the bearing 5 made of sintered metal for supporting the
Is a linear solenoid valve in which the contact between the inner peripheral surface and the outer peripheral surface of the rod 4 is substantially a circular line contact.

The electromagnet section 2 will be further described. In the space between a steel case 11 and a steel sleeve 12 connected to the case 11, a bobbin 13 made of an insulating resin is provided.
, The coil 3 is wound. Bearings 5, 5 are press-fitted and fixed respectively in the center holes of the case 11 and the sleeve 12, and the rod 4 is passed over the bearings 5, 5. A plunger 14 made of steel is located in the center hole of the sleeve 12, and a projection 15 at the center of the plunger 14 is
The plunger 14 and the rod 4 are fixed by being fitted and fixed in a groove 16 formed on the outer periphery of the plunger.

The pressure regulating valve section 1 is similar to a known pressure regulating section. To explain the outline thereof, a valve sleeve 18 provided with a plurality of ports 17 serving as oil passages is fixed to the case 11, and is provided in the valve sleeve 18. The spool 19 coupled to the rod 4 is passed through. The tip of the spool 19 faces the inner end of the valve sleeve 18 via a coil spring 20, and the spool 19 is urged in the direction of the electromagnet section 2. The coil 3 is energized through a terminal 21 provided at the end of the bobbin 13.

FIG. 1 shows a state where the coil 3 is not energized, and the rod 4 is located at the right end. When the coil 3 is energized, the plunger 1
4 slides to the left, and the rod 4 slides as the plunger 14 slides. Then, the sliding position of the rod 4 can be adjusted depending on the degree of the current. With this operation, the positional relationship between each port 17 and the spool 19 changes to perform a valve action, and the hydraulic pressure is proportionally controlled.

According to this embodiment, since the contact between the inner peripheral surface of the bearing 5 and the outer peripheral surface of the rod 4 is substantially a circular line contact, there is little possibility that an extreme increase in sliding frictional resistance is caused. In addition, the centering accuracy of the rod 4 with respect to the bearing 5 can be improved, and deterioration in pressure regulation characteristics can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention (without hatching in order to avoid complicating the drawing);

FIG. 2 is an enlarged sectional view of a main part of the same.

FIG. 3 is an enlarged sectional view of a coaxial receiver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure regulating valve part 2 Electromagnet part 3 Coil 4 Rod 5 Bearing

Claims (1)

[Claims] 1. An electromagnet portion of a linear solenoid valve having a pressure regulating valve portion and an electromagnet portion, wherein an inner peripheral surface of a bearing for axially supporting a rod which is driven linearly by applying a current to a coil and which is used for pressure regulating operation is substantially in section. A linear solenoid valve having an arc shape, in which the contact between the inner peripheral surface of the bearing and the outer peripheral surface of the rod is substantially a circular line contact.