JPH0642321Y2 - Push-type variable resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a push-type variable resistor that adjusts a resistance value by driving a shaft protruding outside a case in an axial direction thereof.

[Conventional technology]

6 and 7 show conventionally known push-type variable resistors.

FIG. 6 is a sectional view of the push-type variable resistor taken along the axial direction of the shaft, and FIG. 7 is a sectional view taken along the direction perpendicular to the axial direction of the shaft. As shown in these planes, this push-type variable resistor mainly includes a case 1, a resistor 2, a shaft 3, and a movable contact 4.
And a return spring 5.

As shown in FIG. 6, the resistor 2 is set along the bottom surface 1c of the case 1, and the movable contact 4 (contact metal fitting 4a) extends from the front plate 1a of the case 1 to the rear plate 1b or vice versa. By moving in the direction, the resistance value can be adjusted.

As shown in this figure, the contact fitting 4a is formed integrally with the shaft 3 via a sliding body 4b. This sliding body 4b
As shown in FIG. 7, an engaging projection 6 for engaging with the case 1 is provided outwardly on the circumferential surface of the shaft 3 at a position symmetrical to the shaft 3 via the shaft 3.

As shown in FIG. 6, the front plate 1a of the case 1 has a through hole 7 penetrating the shaft 3, and the side faces 1d and 1e of the case 1 have the through holes 7 as shown in FIG. A guide groove 8 that engages with the engagement protrusion 6 is provided in the recess. As shown in FIG. 7, the guide groove 8 is formed in parallel with the resistor 2, and guides the movable contact 4 (contact metal fitting 4a) along the resistor 2. .

The combination of the shaft 3 and the movable contact 4 penetrates one end of the shaft 3 into the through hole 7 formed in the front plate 1a of the case 1 and engages with the sliding member 4b so as to project therefrom. The protrusion 6 is retained in the case 1 by engaging with the guide groove 8 provided in the side surfaces 1d and 1e of the case 1.

This push-type variable resistor is capable of sliding the contact fitting 4a along the resistor 2 by driving the tip end of the shaft 3 protruding from the case 1 in the axial direction thereof. Therefore, the resistance value can be adjusted to a value according to the position of the contact fitting 4a.

This push-type variable resistor is used, for example, as a valve opening detection sensor of an exhaust gas recirculation device for an internal combustion engine for automobiles.

[Problems to be solved by the device]

As described above, in the conventional push-type variable resistor, the shaft 3 and the movable contact 4 are integrally formed, and the combination thereof is formed by the through hole 7 of the case 1 and the two guide grooves 8. Three points are supported.

Therefore, the clearance provided between the engaging projection 6 and the guide groove 8, and the through hole and the guide groove 8 with respect to the positional relationship between the shaft line of the shaft 3 and the engaging projection 6.
If the positional relationship with is too strict, when there is thermal deformation or time-dependent deformation during use, there is no room to escape the dimensional difference, the drive of the shaft 3 becomes unsuccessful, and the shaft 3 is driven. If you can't do it, it's easy to cause inconvenience.

Such inconvenience is caused by providing a driving body interlocking with both of the shaft 3 and the movable contact 4 and interlocking the shaft 3, the movable contact 4 and the driving body independently on the inner surface of the case. It can be solved by doing. That is, in this case, a clearance can be provided between the shaft 3, the movable contact 4, and the driving body, and the dimensional error of each member can be absorbed by the clearance.

However, if the movable contact 4 and the driving body are improperly coupled, the movable contact 4 vibrates in the axial direction of the shaft 3 regardless of the driving body, and accurate resistance value adjustment cannot be performed. It causes inconvenience.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and an object thereof is to provide a push-type variable resistor having excellent vibration resistance and high reliability of resistance value adjustment. is there.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a drive member interlocking with both of the shaft and the movable contact,
The shaft, the movable contact, and the driving body are independently held on the inner surface of the case, and the driving body and the movable contact are elastically connected in the axial direction of the shaft.

[Action]

As described above, when the drive body and the movable contact are elastically connected in the axial direction of the shaft, no clearance is generated between the two members in this direction. Therefore, the movable contact does not move in the axial direction of the shaft regardless of the shaft and the driving body. Therefore, erroneous detection of the resistance value does not occur.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

1 is a front sectional view of a push-type variable resistor according to the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG.
FIG. 4 is a sectional view taken along the line BB in FIG. 4, and FIG. 4 is a sectional view taken along the line CC in FIG.

In these drawings, reference numeral 11 denotes a driving body, and the same members as those shown in FIGS. 6 and 7 are designated by the same reference numerals.

The case 1 is formed in what is called a semi-cylindrical shape in which the upper half part is circular and the lower half part is rectangular. The front plate 1a is attached to the front surface of the case 1 to form a hermetically sealed container. The front plate 1a has a through hole 7 penetrating the shaft 3, and the rear plate 1b of the case 1 arranged to face the front plate 1 is shown in FIGS. 2 and 3. Thus, a cylindrical shaft holder 12 is provided upright concentrically with the through hole 7.

Further, as shown in FIG. 1, two guide grooves 13a, 13b are provided in the inner surface of the side plates 1d, 1e of the case 1 at the symmetrical position via the through hole 7, and Two guide grooves 14a and 14b are provided at lower symmetrical positions. These guide grooves 13a, 13b, 14a, 14b are extended in parallel with the axial direction XX of the shaft 3, as shown in FIG. 2 and FIG.

The resistor 2 is set along the bottom plate of the case 1, and three lead terminals 15 are set at one end thereof. Other than that, the relationship between the resistor 2 and the movable contact 4 is the same as in the above-described conventional technique, and thus the description thereof is omitted.

As shown in FIG. 2 to FIG. 4, the shaft 3 has two engaging projections 16a, which project from a position symmetrical with respect to the peripheral surface at a substantially central portion in a direction perpendicular to the axial direction XX of the shaft 3. 16b
Further, a bulge portion 17 is formed at one end accommodated in the case 1 so as to be fitted in the holding body 12 slightly tightly. From the engaging projections 16a, 16b to the case 1
The one end located outside is formed to have a diameter that allows the through hole 7 to penetrate slightly, and the maximum diameter of the bulging portion 17 is formed to have a diameter that allows the shaft holding body 12 to penetrate slightly. To be done.

The shaft 3 is, as shown in FIGS. 2 and 3,
The bulging portion 17 is slidably fitted into the shaft holding body 12 and the other end is slidably pierced into the through hole 7 so that the bulging portion 17 is parallel to the resistor 2. Will be placed.

The driver 11 is formed in a cylindrical shape having a diameter larger than that of the shaft 3, and the shaft 3 has an inner surface near one end thereof.
Engagement piece 1 for engaging the engagement protrusions 16a, 16b projecting on the
8 is projected inward. Further, on the outer peripheral surface of the drive body 11, engagement protrusions 19a, 19b which can be slightly tightly fitted in the guide grooves 13a, 13b provided in the case 1 are provided. Further, an engaging projection 20 for engaging the movable contact 4 is vertically provided below the outer peripheral surface of the driving body 11.

The driving body 11 includes the engaging protrusions 19a and 19b in the case 1
It is set in the case 1 by being fitted into the guide grooves 13a and 13b which are recessed. The engagement piece 18 and the case 1
A return spring 5 is stretched between the rear face plate 1b and the rear face plate 1b, and the driving body 11 is constantly urged toward the front face plate 1a side of the case 1. Further, the driving body 11 includes the engaging piece 18 and the engaging protrusion 16a,
It is engaged with the shaft 3 via 16b and is driven by the shaft 3 to the rear plate 1b side.

As shown in FIG. 4, the movable contact 4 includes a contact fitting 4a, a spring member 21 integrally formed with the contact fitting 4a, and a synthetic resin sliding member integrally molded at both ends of the spring member 21. It consists of moving body 4b.

As shown in FIG. 5, both ends of the sliding body 4b are formed to have a thickness that can be inserted into the guide grooves 14a and 14b formed in the case 1 so as to prevent the elasticity of the spring member 21. Use guide groove
It is designed to be in close contact with the upper and lower surfaces of 14a and 14b.

On the other hand, the central portion of the sliding body 4b is
The spring member is formed to be thicker than the both ends.
An engaging portion 23 for engaging the engaging projection 20 vertically extending from the driving body 11 is formed between the interposing portion 4c and the sandwiching portion 4c which is attached to face it via 21.

The movable contact 4 is mounted in the case 1 by slightly inserting the both ends of the thin slide member 4b into the guide grooves 16a, 16b provided in the case 1. Further, by elastically fitting and engaging the engaging protrusion 20 on the lower surface of the driving body 11 in the engaging portion 23, the engaging projection 23 is engaged with the driving body 11 integrally.

In the push-type variable resistor of the above embodiment, the shaft 3, the movable contact 4, and the driving body 11 are independently held on the inner surface of the case 1, so that the shaft 3 and the driving body 11 and the driving body 11 are connected to each other. Clearance formed between movable contact 4
With 24 and 25, it is possible to escape the dimensional error in the direction orthogonal to the axial direction X-X of the shaft 3. Therefore, the assembling property of each part is improved, the defective product rate is reduced, and the productivity of the push-type variable resistor can be improved.

Further, since the shaft 3, the movable contact 4, and the driving body 11 are formed separately and are supported at two points with respect to the case 1, each member 3, 4, 11 is held in the case 1 slightly tightly. can do. Therefore, by adjusting the frictional force acting between each member 3, 4, 11 and the case 1 to be larger than the external force such as vibration, the inertial force of each member caused by the outside is returned. The spring 5 can be prevented from acting. Thus, the movable contact is prevented from being improperly slid, and the vibration resistance of the push-type variable resistor is improved.

In addition, since the sliding body 4b is elastically inserted into the guide grooves 14a, 14b, the contact state between the contact metal fitting 4a and the resistor 2 is always kept stable, and when the contact metal fitting 4a is separated from the resistor 2, It does not cause any inconvenience.

Further, since the driving body 11 and the movable contact 4 are elastically engaged, the movable contact 4 does not move in the axial direction of the shaft 3 regardless of the shaft 3 and the driving body 11, and the resistance value is erroneously detected. It never happens. Since the drive body 11 is constantly urged by the return spring 5 so as to be in close contact with the shaft 3, the clearance between the shaft 3 and the drive 11 does not pose a problem.

In the above-described embodiment, the case where the shaft 3, the movable contact 4, and the driving body 11 are held by frictional force and no inertial force is exerted on the return spring 5 has been described. If 3 is held by a frictional force, it is effective in improving the vibration resistance.
It is also possible to prevent the friction force from being applied.

Further, the gist of the present invention is to provide a driving body interlocking with both of these members between the shaft and the movable contact, and hold the shaft, the movable contact and the driving member independently on the inner surface of the case, The drive body, and the drive body and the movable contact point are connected by the engaging means that can engage only in the axial direction of the shaft. Therefore, the shapes, materials, etc. of the individual members are the same as those in the above embodiment. It is not limited to one. These can be appropriately designed as needed.

[Effect of device]

As described above, in the push-type variable resistor of the present invention, the driving body and the movable contact are elastically connected with respect to the shaft line direction of the shaft, so that the movable contact can be moved in the shaft line direction of the shaft independently of the shaft and the shaft drive. It never moves. Therefore, it is possible to provide a highly reliable push-type variable resistor without erroneously detecting the resistance value.

[Brief description of drawings]

1 to 5 are views for explaining an embodiment of the push-type variable resistor according to the present invention, in which FIG. 1 is a front sectional view and FIG. 2 is a sectional view taken along line AA of FIG. 3 and 4 are sectional views taken along the line BB of FIG. 1, FIG. 4 is a sectional view taken along the line CC of FIG. 1, and FIG.
The figure is a cross-sectional view showing an engaged state of the sliding body and the case. 6 and 7 are views for explaining a push-type variable resistor according to the prior art. FIG. 6 is a side sectional view,
FIG. 7 is a front sectional view. 1: Case, 2: Resistor, 3: Shaft, 4: Driving body, 5: Sliding body, 6: Moving contact, 11: Driving body.

Claims (1)

[Scope of utility model registration request] 1. A resistor set in a case, and a shaft having one end housed in the case, arranged in parallel with the resistor and held so as to reciprocate in an axial direction.
In a push-type variable resistor having a movable contact that slides on the resistor in conjunction with this shaft, a drive member that interlocks with these members is provided between the shaft and the movable contact, and these shaft and A push-type variable resistor characterized in that a movable contact and a driving body are independently held on the inner surface of the case, and the driving body and the movable contact are elastically connected in the axial direction of the shaft.