JPH059469Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an idle position detection switch for an internal combustion engine.

[Prior Art] In an internal combustion engine, an idle position detection switch is used when controlling the amount of fuel supplied in accordance with the opening degree of a throttle valve.

A conventional example of this is shown in FIG.

That is, in the figure, a substantially cylindrical housing 2 attached to the throttle body 1 includes a push rod 3, a movable contact 4 provided at the lower end of the push rod 3, and a movable contact 4 disposed at a position opposite to the movable contact 4. A fixed contact 5 is provided inside. Note that the throttle body 1 is attached to an engine (not shown) and grounded. The push rod 3 is slidably fitted and supported inside a small diameter portion 6a of a substantially cylindrical guide 6 provided within the housing 2, and its upper end portion protrudes from the opening at the tip of the housing 2. A ring-shaped plate 7 is fitted onto the outer periphery of the lower end of the push rod 3 located inside the large diameter portion 6b of the guide 6. A substantially cylindrical insulator 8 is disposed inside the lower end opening of the housing 2, and the insulator 8 is fitted onto the inner periphery of the housing 2 with its large diameter portion 8a. The small diameter portion 8b of the insulator 8 is fitted onto the outer periphery of the lower end of the push rod 3. A lead plate 9 is interposed between the lower end surface of the large diameter portion 6b of the guide 6 and the end surface of the large diameter portion 8a of the insulator 8. A spring 10 is interposed between the plate 7 and the lead plate 9. Therefore, the push rod 3 is normally moved by the spring 10 to the swinging end 1 of the stopper 12 connected to the valve shaft 11 of the throttle valve.
The stopper 1 is biased in a direction opposite to the stopper 2a.
2, it is slid against the elastic force.

A terminal 13 is coupled to the fixed contact 5, and the terminal 13 is guided to the outside via a resin connector 14 fitted to the inner periphery of the lower end opening of the housing 2. This connector 14 is connected to the housing 2
It is held fixed to the housing 2 by caulking a portion 15 extending further from the lower end opening. The main body of the connector 14 is an insulating cap that closes the opening at the lower end of the housing 2. On the other hand, a threaded portion 2a is formed on the outer periphery of the upper end of the housing 2, and is screwed into a female thread 1a provided on the throttle body 1 using this threaded portion 2a. Note that 16 is a seal rubber attached to the outer periphery of the upper end of the housing 2.

Next, the operation of this configuration will be explained.

When the valve shaft 11 of the throttle valve is rotated in response to the fully closing of the throttle valve, the push rod 3 is pressed by the swinging end 12a of the stopper 12 against the elastic force of the spring 10. A movable contact 4 provided at the lower end of the push rod 3 contacts a fixed contact 5. At this stage, the stopper 12 is positioned. The current from the terminal 13 is then grounded to the fixed contact 5, push rod 3, plate 7, spring 10, lead plate 9, housing 2 and throttle body 1.
The idle position will be detected.

[Problems to be solved by the invention] In the structure of the conventional idle position detection switch as described above, each time the swinging end 12a of the stopper 12 provided on the valve shaft 11 of the throttle valve comes into contact with the push rod, The stress is immediately transmitted from the fixed contact 4 to the connector 14, which is an insulating cap, and weakens the caulked portion 15. Therefore, caulking part 1
5 and the connector 14 is moved backward to change the idle position, or the resin forming the connector 14 may creep in the vicinity of the caulked portion.

This invention was made to solve this problem, and when the swinging end 12a of the stopper 12 provided on the valve shaft 11 of the throttle valve comes into contact with the push rod and hits the fixed contact, the crimped portion To provide an idle position detection switch which weakens the force transmitted to the connector 14 and prevents creep from occurring in the resin forming the connector 14.

[Means for solving the problem] Therefore, the present invention sandwiches a support disk supporting a fixed contact between the lower open end of the housing and an insulating cap that is caulked and fixed to this. The support disk is elastically biased toward the housing.

[Operation] The impact that strikes the fixed contact with the push rod is absorbed by the elastic bias. Even if the caulked part loosens due to long-term use, the elastic bias compensates for this and holds the fixed contact in a fixed position.

[Example] Hereinafter, an example of the present invention will be described based on FIG. 1. In this figure, the same elements as those of the conventional device are given the same reference numerals to simplify the explanation.
17 is a fixed ring provided at the lower end of the push rod 3; 18 is a support disk supporting the fixed contact 5;
Reference numeral 19 indicates a terminal piece that makes electrical contact with the fixed contact 5 supported by the support disk 18, and 20 indicates an end portion of a lead wire crimped onto this terminal piece 19. Reference numeral 22 denotes a step portion formed at the lower open end of the housing 2.

The upper end of the spring 10 has a small turn 10a extending radially inward and matching the small diameter portion of the lower end of the push rod 3. This winding portion 10a is held between the push rod 3 and the plate 7 by fixing a fixing ring 17 to the lower end of the push rod 3. Thus, the upper end of the spring 10 is tightly electrically connected to the movable contact 4 side. The lower end of the spring 10 extends radially outward to form a large winding portion 10b. This large winding part 10b
is located in a guide groove 8e provided on the outer periphery of the insulator 8, and is fastened to the stepped portion 22 of the housing 2. Thus, the lower end of the spring is firmly electrically connected to the housing 2 side. Note that this clamping is achieved at the same time that the connector 14 is fixedly held to the housing 2 by caulking the caulking portion 15.

A radially outwardly extending portion of the lower end of the spring 10 exits through a recess 8d formed in the insulator 8 and is connected to the large winding portion 10b.
As described above, the insulator 8 has a guide groove 8e on its outer circumference. Further, the insulator 8 has a support 8c at a position diametrically opposed to the recess 8d. The large-diameter portion 6b of the guide 6 faces the insulator 8 and substantially surrounds the spring 10, the movable contact 4, etc., and has a large-diameter cutout groove 6c for receiving the support column 8c of the insulator 8. The portion 6b has. A protrusion 7a extending radially from the plate 7 is further engaged with the cutout groove 6c so as to be movable in the axial direction.

The support disk 18 is constructed by cutting out the leaf spring member as shown in FIG. 2a, and is preformed as shown in FIG. 2b. Thus, even if the caulked portion 15 becomes loose as shown in FIG. 2c, the movable contact will rise and the idle position detection point will not be changed. Further, the insulator 8 is lifted up and the lower large diameter winding portion 10b of the spring 10 is sandwiched between the housing.

In this embodiment, the support disc 18 is made of a leaf spring member, but instead of a leaf spring, an elastic body such as a wave washer may be interposed between the support disc 18 and the connector 14, which is an insulating cap. You can leave it there.

Note that a wave washer 21 is provided between the housing 2 and the large diameter portion 6b of the guide 6. A rubber cover 23 surrounds the connector 14.

According to this configuration, the idle position detection point remains unchanged even after many years of use, and furthermore, the impact applied to the crimped portion etc. is reduced, and creep etc. do not occur in the resin member.

[Effects of the invention] As explained above, according to the invention, the movement of the push rod when detecting the idle position can be reliably detected, the idle position detection point will not change even after many years of use, and the impact on the caulking parts etc. can be reduced. The effect is that the reliability of the function of the idle position detector can be improved without causing creep or the like to occur in the resin member.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the idle position detection switch according to the present invention, Fig. 2 is a diagram for explaining the functions performed by the members shown in Fig. 1, and Fig. 3 is a diagram showing a conventional idle position detection switch. FIG. In the figure, 1 is a part of the throttle body, 2
is a housing, 3 is a push rod, 4 is a movable contact, 5 is a fixed contact, 10 is a spring, 10a is one end of the spring, 10b is the other end of the spring,
18 indicates a support disk. Note that the same reference numerals in each figure indicate the same members or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] (1) A metal housing fixed and supported by the throttle body and electrically connected to the body, which is attached to the housing so as to be slidable in the axial direction, with one end protruding from the housing. a push rod that is in contact with a stopper provided on the valve shaft of the throttle valve, a movable contact provided at the inner end of the push rod, and a fixed insulatingly fixed to the housing at a position opposite to the movable contact. a contact and a metal spring biasing the push rod back to its initial position, the spring also having the function of grounding the movable contact to the housing and thus In an idle position detection switch in which both contacts come into contact and generate an idle position signal when the stopper comes into contact with a push rod, the supporting disk supporting the fixed contact in the center is insulated around the supporting disk to the housing. An insulating cap is caulked and fixed to the open end of the housing for clamping and fixing, and an elastic device biases the support disk toward the housing even if the caulking is loosened, and supports the solid contact. An idle position detection switch characterized in that said supporting disk substantially stops axial inward movement of said push rod. (2) The idle position detection switch according to claim 1, wherein the elastic device has a supporting disk formed from a plate spring and also serves as a supporting disk.