JPH0932946A - Variable throttling mechanism for fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform stable regulation of a fine flow rate throughout a long period by a method wherein a helical groove is formed in the peripheral surface of a spool, and the spool is slidably placed in a sleeve located in a housing. SOLUTION: A variable throttle mechanism for fluid comprises a sleeve 2 securely arranged at a housing 3; a spool 1 placed in the spool 2; and a fixed nut 4 to hold the fixing state of the disposing position of the spool 1. The spool 1 is provided on the peripheral surface of the base end side with a female screw 21 formed in the end part of the inner peripheral surface of the sleeve 2 and a male screw 12 joined in a screwed-in state with a fixing nut 4 and on the end face on the base end side with an operation groove 13 so that it can be operated by a driver. Further, a helical groove 11 is formed in a peripheral surface on the tip side. In which case, the spool 1 is placed in the sleeve 2 slidably in such a manner that a position is regulatable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid variable throttling mechanism, and more particularly to a fluid variable throttling mechanism capable of stably adjusting a minute flow rate.

[0002]

2. Description of the Related Art Conventionally, a fluid throttling mechanism arranged in the middle of a fluid passage for the purpose of adjusting the flow rate of fluid such as hydraulic oil and air is shown in FIG. The method of adjusting the flow rate by providing the orifice 5 and FIG.
The method of adjusting the flow rate by providing the needle valve 6 as shown in (b) is widely used.

[0003]

By the way, in the method of using an orifice among the above-mentioned conventional fluid throttling mechanisms, the throttling amount of the fluid is determined by the shape of the orifice.
There is a problem that the flow rate cannot be variably adjusted. Further, any of the above methods is included in the fluid because it regulates the flow rate by the fluid resistance when the fluid passes through a very fine gap formed by narrowing the flow passage and having a short flow passage length. It has been difficult to stably adjust a minute flow rate for a long period of time because dust or the like is clogged in this minute gap.

The present invention solves the problems of the conventional fluid throttling mechanism, and provides a variable fluid throttling mechanism which enables stable adjustment of a minute flow rate over a long period of time. The purpose is to

[0005]

In order to achieve the above object, the fluid variable throttle mechanism of the present invention has a spiral groove formed on the circumferential surface of a spool, and the spool is provided in a sleeve provided in a housing. It is characterized in that it is slidably arranged.

According to the fluid variable throttle mechanism of the present invention, the length of the spiral groove of the spool, which is in contact with the inner peripheral surface of the sleeve, is operated by sliding the spool slidably disposed in the sleeve provided in the housing. That is, the flow rate is adjusted by changing the effective length of the groove that becomes the fluid resistance.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a fluid variable throttle mechanism of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of a fluid variable throttle mechanism of the present invention. The fluid variable throttle mechanism includes a housing 3 and a sleeve 2 fixed to the housing 3.
And spool 1 arranged in sleeve 2 and sleeve 2
And a fixing nut 4 for holding the fixed position of the spool 1 inside.

The spool 1 has a sleeve 2 on the peripheral surface on the base end side.
Female screw 21 and fixing nut 4 formed at the end of the inner peripheral surface of the
In addition to forming a male screw 12 that is screwed with, an operation groove 13 is formed on the end face on the base end side so that it can be operated by a driver and the like, and a spiral groove 11 is formed on the peripheral surface on the tip end side. The spool 1 is arranged in the sleeve 2 so as to be slidable and positionally adjustable.

The inner peripheral surface of the sleeve 2 and the peripheral surface of the spool 1 on which the spiral groove 11 is formed on the front end side are in sliding contact with each other except for the enlarged diameter portion 22 formed in the middle of the sleeve 2.
In the portion where both are in sliding contact, the fluid can pass through only the portion of the substantially spiral groove 11. As a result, the spool 1 slidably disposed in the sleeve 2 is slidably operated by a driver or the like, and the length of the spiral groove 11 of the spool 1 in contact with the inner peripheral surface of the sleeve 2, that is, the fluid resistance and The flow rate is adjusted by changing the effective length of the groove 11. The state shown in FIG. 1 is a state in which the length of the spiral groove 11 of the spool 1 which is in contact with the inner peripheral surface of the sleeve 2 is the longest, that is,
The state where the flow rate of the fluid is the smallest is shown.

By changing the length and cross-sectional area of the spiral groove 11 formed on the peripheral surface of the spool 1 on the tip side, the design value of the flow rate of the fluid can be arbitrarily set by using the spool 1 having the same diameter. can do.

In the above embodiment, one spiral groove 11 is formed on the peripheral surface of the spool 1 on the front end side. However, the spiral groove is formed on the peripheral surface of the spool 1 on the front end side. It is also possible to form two or more streaks 11 so that the design value of the flow rate of the fluid can be arbitrarily set using the spool 1 of the same diameter without changing the cross-sectional area of the spiral groove 11 of one streak. Can be set. In this case, the spiral groove 11
Are preferably formed so that the spiral grooves 11 are opened at substantially equal intervals on the circumferential surface of the spool 1 on the tip side, that is, on the end surface of the spool 1 at the tip side.

As described above, in the fluid variable throttle mechanism of the present invention having the above-described structure, the length of the spiral groove 11 of the spool 1 in contact with the inner peripheral surface of the sleeve 2, that is, the groove 11 serving as a fluid resistance. Since the minute flow rate can be adjusted stably over a long period of time by changing the effective length of the, the flow rate control mechanism of the control device in the fluid machine that has conventionally used an orifice or a needle valve. In addition to improving the performance of the fluid machine or the like, it can be widely applied to applications such as a damper mechanism.

[0014]

According to the fluid variable throttle mechanism of the present invention,
Since the spiral groove is formed on the peripheral surface of the spool, it is possible to lengthen the flow path length that becomes the fluid resistance. Therefore, compared with the conventional fluid throttling mechanism with a short flow path length. , The gap, that is, the cross-sectional area of the groove can be set large, so that even if the fluid contains dust,
The groove is unlikely to be clogged, and a minute flow rate can be adjusted stably over a long period of time. Further, this makes it possible to configure the high-performance fluid variable throttle mechanism to be extremely compact.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a fluid variable throttle mechanism of the present invention.

2A and 2B show a spool of the fluid variable throttle mechanism of the present invention, FIG. 2A is an external view thereof, and FIG.

FIG. 3 is a sectional view showing an example of a conventional fluid throttling mechanism.

[Explanation of symbols]

 1 Spool 11 Helical Groove 12 Screw Part 13 Operating Part 2 Sleeve 3 Housing

Claims (1)

[Claims] 1. A variable throttling mechanism for a fluid, wherein a spiral groove is formed on a peripheral surface of a spool, and the spool is slidably disposed in a sleeve provided in a housing.