JPH051880Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a pressure-sensitive switch device for a vehicle that operates in response to atmospheric pressure fluctuations.

(Prior Art) This type of pressure-sensitive switch device has conventionally been used, for example, in an internal combustion engine of an automobile, to compensate for fluctuations in engine operating conditions due to atmospheric pressure fluctuations. The micro switch is configured to operate by the movement of the bellows, which expands and contracts with changes in air pressure.To set the operating height of such a pressure-sensitive switch device, first adjust the lower end position of the bellows, and then attach the mounting screw part of the bellows with adhesive. This is done by fixing it.

(Problem that the invention aims to solve) However, such pressure-sensitive switch devices are usually placed in locations that are susceptible to the effects of heat from the engine, and micro switches in particular are made of resin, so they are susceptible to cold and heat cycles. tends to cause thermal creep. Due to such dimensional changes due to thermal creep of the micro switch, the screw wobbles by the difference in diameter from the mounting hole, resulting in the micro switch's actuating piece being misaligned and not operating at the predetermined altitude or pressure. . In other words, the operating pressure of such a pressure-sensitive switch device is used for high-altitude advance control by controlling the distributor via the igniter, and
When used for high altitude EGR control by controlling VSV (vacuum switching valve) via ECU, the atmospheric pressure is generally 650mmHg to 690mmHg.
It is desirable to switch between ON and OFF in the mmHg range, but even on the lower pressure side, that is, on the high altitude side.
If it remains OFF, the engine will not advance and afterburn will occur, deteriorating drivability, and the VSV will not open, making it impossible to meet exhaust gas regulations. On the other hand, if it remains ON on the high pressure side, that is, on the lowland side. If the angle remains advanced, NOx will increase and knotting will occur more easily, and VSV will remain open and EGR will increase.
If the amount is too large, drivability will deteriorate.

(Means for Solving the Problems) In view of the above drawbacks of the prior art, the pressure sensitive switch device for a vehicle of the present invention has a micro switch 4 and a groove 1b with an open top surface for accommodating the micro switch 4. a case 1, and an atmospheric pressure fluctuation detection device 1 attached to the case 1 to operate the micro switch 4 according to atmospheric pressure fluctuations.
9. A pressure-sensitive switch device for a vehicle, comprising:
A plurality of horizontal through holes 8 are formed in the micro switch 4 at appropriate intervals in the longitudinal direction, and the case 1
A plurality of horizontal screw holes 9 are formed in the peripheral wall of the groove 1b at positions corresponding to the through holes 8 of the micro switch 4, so that the micro switch 4 is inserted into each through hole 8 and into the corresponding screw hole 9. The micro switch 4 is fixed to the circumferential wall of the groove 1b of the case 1 in a crimped manner by a plurality of screws 7, and the atmospheric pressure fluctuation detection device 1 is attached to the lower part of the micro switch 4 through the bottom wall of the groove 1b.
9, an actuating piece 6 that can be moved up and down is arranged, and an elastic member 11 for biasing the micro switch 4 upward is arranged between the lower surface of the micro switch 4 and the bottom wall of the groove 1b. , the elastic member 1
The micro switch 4 is held in contact with a plurality of screws 7 by the biasing force of 1, and is held at the mounting position by the screws 7.

(Function) According to the configuration of the present invention described above, the microswitch 4 is fixed to the peripheral wall of the groove 1b of the case 1 in a crimped state, so that its vertical position is normally maintained. In this state, if the screws 7 become loose due to deformation of the microswitch 4 due to thermal creep or vibrations during vehicle operation, the holding force of the screws 7 in the vertical position by tightening them will be lost. However, the micro switch 4
Due to the biasing force, it comes into contact with and latches onto the plurality of screws 7 and is held in the same position as the attachment position by the screws 7, so that the vertical position relative to the case 1 can still be maintained.

Since the vertical position of the micro switch 4 is maintained in this way, the vertical positional relationship of the actuating piece 6 with respect to the atmospheric pressure fluctuation detection device 19 attached to the lower part of the micro switch 4 is always kept constant, and the micro switch 4 is 4 is atmospheric pressure fluctuation detection device 1
9 allows it to always operate at a predetermined altitude.

Furthermore, since the screws 7 are inserted into the horizontal through holes 8 of the microswitch 4 and are screwed together with the peripheral wall of the groove 1b, and are provided in plural numbers in the longitudinal direction of the microswitch 4, the screws 7 themselves may become loose. Since the function of preventing separation from the groove 1b can still be maintained, together with the position holding function of the elastic member 11, the function of holding the position of the micro switch 4 in the vertical direction is further enhanced.

(Example) Next, an example of this invention will be described with reference to FIGS. 1 to 5.

FIG. 1 shows a pressure-sensitive switch device for compensating for fluctuations in operating conditions of an automobile engine due to fluctuations in atmospheric pressure. Reference numeral 1 designates a case, and a first groove 1a that is rectangular in plan view with an open upper end; , this first groove 1a
A concave groove-shaped second groove is continuously formed in a stepped manner below the
A groove 1b, a circular hole 1c in plan view formed continuously below the second groove 1b, and this hole 1c.
It has a small hole 1d which is formed continuously and has an open bottom end.

2 is a rubber boot that is press-fitted into the first groove 1a of the case 1 to prevent water from entering, and has a downward opening 2a on the bottom surface, and the harness 3, 3
is held.

4 is a resin micro switch housed in the second groove 1b of the case 1, the upper part has terminals 5 to 5 for connecting the harnesses 3 and 3, and the lower part has the actuating piece 6 inserted into the hole of the case 1. 1c in a protruding state. The structure of such a microswitch is well known, and detailed explanation will be omitted.

7, 7 are screws for crimping and fixing the micro switch 4 to the case 1, and the shaft portions 7a, 7a are inserted into the through holes 8, 8 provided in the micro switch 4 on the inner and lower surfaces of the through holes 8, 8. As shown in FIG. 2, they are inserted into screw holes 9, 9 (only one shown) formed in the wall 1e of the second groove 1b of the case 1. Further, the screws 7, 7 are each tightened with a flat washer 10 interposed between the head 7b and the wall surface of the microswitch 4 facing the screw, so that the microswitch 4 is fixed by pressure.

Reference numeral 11 denotes a leaf spring interposed between the lower surface of the micro switch 4 and the bottom of the second groove 1b inside the second groove 1b of the case 1, and as shown in FIGS. On both sides of the cutout groove 12 provided corresponding to the actuation piece 6, a first spring portion 11a is formed in an upwardly curved shape and a second spring portion is partially cantilevered and bent upward. 11b, the first spring part 11a is applied to the gap 13 on the wide side between the stepped lower surface of the micro switch 4 and the bottom of the second groove 1b, and the second spring part 11b is applied to the narrow side. They are respectively located in the gaps 14.

Reference numeral 15 denotes a rod for pushing the actuating piece 6 of the micro switch 4. The upper part is located in the hole 1c of the case 1, the lower part is located in the small hole 1d and extends downward, and the middle part is located at the bottom of the hole 1c. It has a collar 15a that is locked to. A coil spring 16 is interposed between the collar 15a of the rod 15 and the lower surface of the micro switch 4 in the hole 1c, and constantly biases the rod 15 downward.

A lower cover 17 is attached to the lower part of the case 1 via a gasket 18, and contains a bellows 19 that expands and contracts in response to atmospheric pressure. A guide 20 is attached to the bottom of the lower cover, and the position of the bellows 19, that is, the atmospheric pressure fluctuation detection device is adjusted by moving the shaft portion 19a at the lower end along the guide 20. After adjustment, the shaft portion 1
9a is fixed with adhesive or the like. Due to this adjustment, when the atmospheric pressure is below 650 mmHg to 690 mmHg, the bellows 19 is in a protruding state, pushing the rod 15 upward against the coil spring 16, pushing the actuating piece 6 and turning the micro switch 4 into the ON state. When the temperature exceeds 650 mmHg to 690 mmHg, the bellows 19 is set to contract and the micro switch 4 is turned off, and this signal is transmitted through the harnesses 3 and 3 to the igniter 21 as shown in FIG. Day distributor 22
It is guided to the high altitude advance angle control, and is also guided to the VSV 24 via the ECU 23 and used for high altitude EGR control. Note that the circuits and mechanisms for performing such control and the mechanism for expanding and contracting the bellows 19 are well known and are not directly related to the present invention, so detailed explanations thereof will be omitted.

Next, the operation of the above embodiment will be explained with particular reference to the mounting structure of the microswitch 4, which is a feature of the present invention.

As mentioned above, the pressure-sensitive switch device of this embodiment is for compensating for fluctuations in the operating state of an automobile engine due to fluctuations in atmospheric pressure. For this reason, it is susceptible to the effects of engine heat and vibration, and in particular, since the micro switch 4 is made of resin, it is prone to distortion due to thermal creep over time.If such distortion occurs as shrinkage in the thickness direction, the screw 7 ,7
loosens, making it impossible to hold the microswitch 4. However, such screws 7, 7
Even if the micro switch 4 becomes loose, the leaf spring 1
1, the lower surfaces of both sides of the through holes 8, 8 are pressed upward with substantially equal force by the first spring portion 11a and the second spring portion 11b of 1, so that the lower surfaces of the through holes 8, 8 are pressed against the lower surfaces of the screws 7, 7. In other words, the microswitch 4 is locked by the screws 7, 7, and the vertical position of the microswitch 4 is maintained at the same position as the mounting position by tightening the screws 7, 7. Therefore, the positional relationship between the operating piece 6 of the microswitch 4 and the bellows 19, that is, the rod 15 of the atmospheric pressure fluctuation detection device, is maintained in its original state, and the pressure-sensitive switch can be operated at the initial set pressure.

(Effect of the invention) This invention allows the microswitch to maintain its upper and lower positions against the screw due to the biasing force of the elastic member, even if the screw is loosened due to deformation of the microswitch due to thermal creep or vibrations during vehicle operation or engine vibration. The locking action still allows it to be held in the screwed position. Therefore, the microswitch can always operate at a predetermined altitude using the atmospheric pressure fluctuation detection device, so it has the advantage of always being able to properly correct fluctuations in engine operating conditions due to atmospheric pressure fluctuations. Furthermore, since the screw itself can be used as a means for holding the microswitch in the screw-mounted position in cooperation with the elastic member, there is an advantage that the structure is simplified.

[Brief explanation of the drawing]

Figures 1 to 5 show examples of this invention, with Figure 1 being a longitudinal sectional view of the temperature-sensitive switch, and Figure 2 being a partial cross-sectional view taken along the - line in Figure 1. , FIG. 3 is an enlarged front view of the leaf spring shown in FIG. 1 in an unloaded state, FIG. 4 is a plan view of FIG. 3,
FIG. 5 is a block diagram showing an example of high altitude advance angle control and high altitude EGR control using a pressure sensitive switch. 1... Case, 1b... Second groove (concave groove), 4...
...Micro switch, 6... Actuation piece, 7,7...
Screw, 8, 8... Through hole, 9, 9... Screw hole, 1
1...Plate spring (elastic member), 19...Bellows (atmospheric pressure fluctuation detection device).

Claims (1)

[Scope of utility model registration request] A case including a microswitch, a groove with an open top surface for accommodating the microswitch, and an atmospheric pressure fluctuation detection device attached to the case to operate the microswitch in accordance with atmospheric pressure fluctuations. A pressure sensitive switch device for a vehicle, wherein the micro switch is provided with a plurality of horizontal through holes at appropriate intervals in the longitudinal direction, and the peripheral wall of the groove of the case is provided with the through holes of the micro switch. A plurality of horizontal screw holes are formed in the portions corresponding to the holes, and the microswitch is inserted into the peripheral wall of the groove of the case by a plurality of screws that are inserted into the through holes and screwed into the corresponding screw holes. The microswitch is fixed in a crimped state, and an actuating piece that can be moved up and down by the atmospheric pressure fluctuation detection device through the bottom wall of the groove is disposed at the lower part of the microswitch. An elastic member is disposed between the bottom wall and the microswitch to urge the microswitch upward, and the microswitch is held in contact with the plurality of screws by the urging force of the elastic member, and the microswitch is held in contact with the plurality of screws. A pressure-sensitive switch device for a vehicle, characterized in that the pressure-sensitive switch device is configured to be held at an installed position by the pressure-sensitive switch device.