JP2000322966A - Body earth device for switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a body earth device for a switch capable of always keeping a body earth path even if mutual looseness between components occurs in the switch and capable of carrying out a stable detecting operation. SOLUTION: A conductive diaphragm constituting member 16 is formed in a joint 12, a conductive plate spring 1 is inserted onto it by guiding it with a plate spring guiding jig, a conductive inside terminal 20 on which an elastic arm 26 is fixed is mounted on it, a connector is inserted from the upper side thereof and integrated by crimping it at a caulking part 23. The plate spring 1 is provided with a press-contact supporting part 2 brought into press contact with the inside wall of the joint on its circumference, and a pressing part 4 constrictively installed between the inside terminal 20 and diaphragm members in its inside, and the plate spring 1 always makes the terminal 20 in the upper part abut on the joint 12 on the circumference with its elasticity and forms a secure body earth path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch body grounding device for grounding a circuit by a pressure switch for detecting a positive pressure or a negative pressure such as a hydraulic pressure or a lubricating hydraulic pressure of an automatic transmission of an automobile. .

[0002]

2. Description of the Related Art A motor vehicle is provided with a pressure switch for detecting lubricating oil pressure in order to detect whether lubricating oil pressure is appropriate or to detect an operating state of an engine.
In addition, various pressure switches are used, such as a positive pressure / negative pressure detection pressure switch, for detecting the intake pressure, exhaust pressure, crank chamber pressure, operating pressure of various control actuators, and the like of the engine.

As shown in FIG. 7, for example, these pressure switches are provided in a joint 62 made of a conductive material having a fixed part 61 which contains a fluid to be detected and is screwed to a vehicle device 60 such as a transmission. A diaphragm component 66 having a diaphragm 65 sandwiched between an upper cover 63 and a lower cover 64 made of a conductive material is inserted through an O-ring 67, and an internal terminal 70 is placed thereon, and the outer periphery is pressed down to press them. A connector 71 made of resin and having an O-ring 68 attached thereto is placed over the outer peripheral step 72 of the connector 71, and a caulking portion 73 at the opening end of the joint 62 is caulked to be integrated. A through hole 74 is provided at the center of the internal terminal 70, and the operating shaft 7 is
5 is slidably fitted, and U is
A base end of a conductive elastic arm 76 bent in a letter shape is fixed, and a movable contact 77 is fixed to a front end of the elastic arm 76.

A lower end surface 78 of the operating shaft 75 is in contact with the diaphragm 65 through an opening 80 in the upper cover 63, and an upper end surface 81 is in contact with an operating portion 82 of the elastic arm 76. In the state of the pressure switch 83 shown in FIG. 7, the pressure in the working chamber 84 below the diaphragm 65 is lower than a predetermined pressure.
When the return force of No. 6 and the diaphragm 65 have reversal characteristics, the diaphragm 65 is positioned below in the figure by a force such as a reversal prevention force. Therefore, the operating shaft 75 is located at a lower position as the center position of the diaphragm is lowered, the operating portion 82 of the elastic arm 76 is lowered, and the movable contact 77 is separated from the fixed contact 85. The fixed contact 85 is fixed to an end of a connection terminal 86 bent into an L shape, and the connection terminal 86 extends into a connection recess 87 of the connector 71,
A connection section 88 for connecting to an external ECU or the like is provided.

When the pressure switch 83 is fixed to the transmission and used, when the internal oil pressure is low, the pressure switch 83 shown in FIG.
In this state, as the hydraulic pressure in the working chamber 84 increases, the central portion of the diaphragm 65 rises and the working shaft 75 rises. When the pressure rises above a predetermined oil pressure and the central portion of the diaphragm 65 rises above the neutral position, the diaphragm 65 reverses as shown in FIG. 8 and comes into contact with the lower end surface of the upper cover 63 and stops. As a result, the operating shaft 75 is at the raised position, and pushes up the elastic arm 76 to press the movable contact 77 at the distal end thereof against the fixed contact 85.

[0006] Thus, the current of the circuit connected to the connection terminal 86 is reduced by the connection terminal 86 and the fixed contact 8.
5, movable contact 77, elastic arm 76, internal terminal 7
0, through the upper cover 63 and the joint 62,
The body of the transmission as the on-vehicle device 60 is grounded and short-circuited. This short-circuit signal is detected by the vehicle ECU,
Used as various control signals as described above.

[0007]

In the above conventional body earthing device for a switch, when the switch is provided at a position close to a high-temperature engine in an engine room of a high-temperature automobile, the temperature of the switch is about 150 ° C. May rise. On the other hand, when the car is not used, the temperature becomes almost the same as the outside temperature, which may be -20 ° C in a cold region in Japan, or about -40 ° C in a foreign country. When the vehicle is continuously used from this low temperature state and the load increases, the temperature immediately rises to about 150 ° C., and the temperature immediately drops after the vehicle is not used.

[0008] As described above, when the above-mentioned switch is used in a place where the temperature change is large, especially when the metal joint 6 is used.
Due to the difference in the coefficient of thermal expansion between the connector 2 and the resin connector 71,
The portion of the connector 71 sandwiched between the caulking portion 73 and the internal terminal 70 may be deformed by compression, and the caulking portion 73 at the open end of the joint 62 that integrates the two may be deformed. As a result, a gap is formed between the caulked portion 73 of the joint 62 and the outer peripheral step 72 of the connector 71 or between the internal terminal 70 and the upper cover 63. Due to this gap, the connector 71 moves up and down in the joint 61, and the internal terminal 70 held between the upper covers 63 by the connector 71 also moves up and down.

At this time, the connector 71 moves up and down due to the vibration of the vehicle while receiving the friction of the sealing action of the O-ring 68. For example, as shown in FIG. While being pressed, the internal terminal 7 together with the connector 71
0 may rise and may be separated from the upper cover 63. When the internal terminal 70 separates from the upper cover 63 in this manner, this part of the body earth path is cut, and the body earth path is cut when the hydraulic pressure is high. Is incorrectly detected as low oil pressure,
Erroneous control is performed in the ECU.

Therefore, the present invention provides a body earthing device for a switch which can maintain a body earthing path at all times even if the parts are loosened in the switch and can perform a stable detection operation. The purpose is to provide.

[0011]

Accordingly, in order to solve the above-mentioned problems, the present invention provides a conductive joint for fixing a switch member having a movable contact in a conductive joint fixed to a body, This is a switch body grounding device provided with a conductive disc spring that is always in contact with both the terminal and the joint.

[0012] Further, a conductive sensor member is fixed in the joint, the disc spring is contracted between the sensor member and the terminal, and both are electrically connected. A pressure contact support portion is provided on the outer periphery and press-fitted to the inner periphery of the joint, and a press portion is provided on the inner periphery side and presses against the terminal.

[0013]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example in which the present invention is applied to a pressure switch for detecting a pressure such as a hydraulic pressure of a transmission. The basic structure is the same as that of the conventional pressure switch shown in FIG. A diaphragm component 16 is inserted into a joint 12 made of a conductive material having a fixing portion 11 screwed to the vehicle device 10.
The diaphragm component 16 is press-fitted via a ring 17 and has a structure in which a diaphragm 15 is sandwiched between an upper cover 13 and a lower cover 14 made of a conductive material. Are integrally formed by welding. Further, the welded portion 19 is always in pressure contact with the inner surface of the joint 12.

The disc spring 1 described later is placed on the upper cover 13 and the internal terminal 20 is placed thereon.
And put an O-ring 18 around the
Is attached to the connector 21 made of resin. The pressure switch is integrated by caulking a caulking portion 23 at the opening end of the joint 12 to the outer peripheral step portion 22 of the connector 21. A base end of a conductive elastic arm 26 bent in a U-shape is fixed to the internal terminal 20 by caulking, and a movable contact 27 is fixed to a distal end of the elastic arm 26. Further, a through hole 24 is provided at the center of the internal terminal 20, and an operating shaft 25 is slidably fitted in the through hole 24.

The upper end surface 31 of the operating shaft 25 is
And the lower end surface 28 is in contact with the upper cover 13.
Through the opening 30 of the diaphragm 15.
When the pressure switch 33 is in the state shown in FIG. 1, the hydraulic pressure in the lower working chamber 34 of the diaphragm 15 is higher than a predetermined pressure, so that the diaphragm 15 is pushed up by the hydraulic pressure and is located at an upper position in the figure. For this reason, the operating shaft 25 is pushed up by the diaphragm 15 and is positioned above, raises the operating portion 32 of the elastic arm 26, and the movable contact 27 is pressed against the fixed contact 35. The fixed contact 35 is fixed to an end of a connection terminal 36 bent in an L shape, and the connection terminal 36 is connected to the connection recess 3 of the connector 21.
7 to form a connection 38 with an external ECU or the like.

As shown in FIG. 2, the disc spring 1 has eight press-contact supporting portions 2 on the outer periphery and an annular bottom wall portion 3 on the inner peripheral side.
And a pressing portion 4 that rises upward from the inner peripheral side of the bottom wall portion 3. At the tip of the base portion 7 of the press-contact supporting portion 2, it is bent upward by about 45 A pressing portion 5 for pressing is formed, and the pressing portion 4 forms four pressing pieces by forming four cuts 6 in the drawing. Thereby, in the mounting state to the pressure switch shown in FIG. 1, the press contact portion 5 of the press contact support portion 2 is always pressed against the inner surface of the joint 12 to maintain the contact state, and the pressing portion 4 is in contact with the lower surface of the internal terminal 20 The contact state is maintained by constantly pressing the upper surface of the upper cover 13, and therefore, the inner terminal 20 is formed by the disc spring 1 itself.
The body ground path from the to the joint 12 is formed.
In addition, as the disc spring, in the above-described embodiment, the press-contact supporting portion 2 is used.
Are formed, and four cuts 6 are formed. However, these can be set to any number, and the outer terminal is pressed against the inner surface of the joint, and the inner terminal 20 is connected to the inner terminal. Disc springs of various shapes other than the above shapes can be used as long as they can be pushed up.

When the hydraulic pressure inside the transmission equipped with the pressure switch is high, the state shown in FIG. 1 is maintained. From this state, the hydraulic pressure of the transmission decreases and the working chamber 3
When the oil pressure in the diaphragm 4 decreases, the return force of the elastic arm 26 acts on the diaphragm 15 from above in the figure, and the oil pressure acts on the diaphragm 15 from below, and a force such as an inversion prevention force acts when the diaphragm 15 has an inversion characteristic. When the force from is stronger, the center of the diaphragm 15 gradually descends. Initially, the elastic arm 26 provided with the movable contact 27 is in a state of being bent by being urged by the operating shaft 25, so that the movable contact 27 does not separate from the fixed contact 35 even if the operating shaft 25 is slightly lowered. However, when the center of the diaphragm 15 further descends and goes beyond the reversal area of the diaphragm, the center of the diaphragm 15 reversely operates downward, and the operating shaft 25 instantaneously descends to the position shown in FIG. Reference numeral 27 rapidly separates from the fixed contact 35, and performs a reliable switch OFF operation.

When the hydraulic pressure rises from the state shown in FIG. 3, as described in the description of the conventional example, the operation is reversed, and as the hydraulic pressure rises, the diaphragm 15 moves.
At the center gradually rises, and the operating shaft 25 also rises together.
When the pressure rises above a predetermined oil pressure and the central portion of the diaphragm 15 rises above the neutral position, the diaphragm 15 reverses as shown in FIG. 1 and comes into contact with the lower end surface of the upper cover 13 and stops. As a result, the operating shaft 25 becomes the raised position,
The elastic arm 26 is pushed up to move the movable contact 2 at the tip thereof.
7 is pressed against the fixed contact 35. As a result, the current of the circuit connected to the connection terminal 36 is changed to the connection terminal 3
6, the fixed contact 35, the movable contact 27, the elastic arm 26, and the internal terminal 20, as a first path, through the pressing part 4, the bottom wall part 3, and the pressure contact part 5 of the disc spring 1, and the joint 12
And the body is grounded to the vehicle body. Further, as another body grounding route, the body flows from the internal terminal 20 through the pressing portion 4, the bottom wall portion 3, and the upper cover 13 of the disc spring 1 to the joint 62 which comes into contact with the welding portion 19 on the outer periphery thereof, and is body grounded. Routes are also possible. This short-circuit signal is detected by the vehicle ECU and used as various control signals as described above.

Considering the operation of the disc spring 1 in detail,
As shown in the enlarged view of FIG. are doing. Further, the upper end of the pressing portion 4 is pushed down by the internal terminal 20 when assembling a disc spring described in detail later, and the upper end is strongly pressed against the lower surface of the internal terminal 20 by the repulsive force. Further, the lower surface of the bottom wall 3 of the disc spring 1 is pressed against the upper surface of the upper cover 13 by the repulsive force. Thereby, of the two short-circuit paths, a short-circuit path passing at least from the bottom wall 3 of the disc spring 1 to the press-contact portion 5 is secured, and a short-circuit path passing from the bottom wall 3 to the upper cover 13 is also secured. The repulsive force of the disc spring 1 acts to lift the connector 21 via the internal terminal 20, thereby preventing the connector 21 and the internal terminal 20 from moving up and down as in the conventional example.

As shown in FIG. 5, the O-ring 17 is inserted from above and the diaphragm component 16 is inserted from above with the caulked portion 23 at the upper end of the joint 12 upright. Next, as shown in FIG. 6, from above the joint 12 on which the disc spring is set, the operating shaft 25 and the elastic arm 26
Then, the internal terminal 20 fixed by caulking and the connector 21 provided with the O-ring 18 on the outer periphery are inserted in order, and finally, the caulking portion 23 at the upper end of the joint 12 as shown in FIG.
Are crimped on the outer peripheral step portion 22 of the connector 21 to integrate them.

In the above-described embodiment, an example is shown in which the present invention is used as a switch for detecting the hydraulic pressure of the transmission. For example, the present invention is used to detect whether the lubricating hydraulic pressure is appropriate or to detect the operating state of the engine. It can also be used as a pressure switch to detect the lubricating oil pressure, as a pressure switch to detect the intake pressure, exhaust pressure, crankcase pressure of the engine, or to detect the operating pressure of various control actuators, etc. Pressure switch for detecting various positive pressures and negative pressures. Further, the present invention is not limited to the pressure detection switch. For example, in the above-described embodiment, the operating shaft for moving the movable contact may be configured to operate in accordance with the expansion of the thermowax, and may be configured as a temperature switch. Can be used for switches.

[0022]

According to the invention of claim 1 of the present application, even if the fixing portion of the joint and the connector is loosened due to a temperature change during use, the conductive terminal and the conductive joint may be separated from each other. Since the disc spring keeps both connected at all times, poor conduction can be prevented. In addition, since this connection state is maintained by the disc spring, there is almost no dimensional change compared to the conventional one, and it can be easily applied without any special design change.

According to a second aspect of the present invention, a conductive sensor member is fixed in the joint, the disc spring is contracted between the sensor member and the terminal, and both are electrically connected. The conductive sensor member and the terminal can be always connected by the contraction force, and the second path can be formed in addition to the first path of the body ground, so that the body ground path is reliably maintained. Can be.

According to a third aspect of the present invention, the disc spring includes a press-contact support portion press-fitted to the inner periphery of the joint on the outer periphery, and a press portion press-contact to the terminal on the inner periphery side.
One disc spring can perform both pressure contact with the joint located in the outer peripheral direction and pressure contact with the terminal located in the vertical direction. Also, the entire disc spring is bent in the vertical direction by the pressure contact force of the disc spring against the inner wall of the joint, and the pressure contact force to the terminal can be maintained for a long period of time by this bending force.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which a switch of an apparatus according to an embodiment of the present invention is ON.

FIG. 2 is an embodiment of a disc spring used in the above device,
(A) is a plan view, (b) is a cross-sectional view taken along the line AA of (a), and (c) is a perspective view.

FIG. 3 is a cross-sectional view showing a state where a switch of the device is OFF.

FIG. 4 is a partially enlarged sectional view of FIG. 3;

FIG. 5 is a sectional view showing a first state during assembly of the device.

FIG. 6 is a sectional view showing a fifth state during assembly of the device.

FIG. 7 is a cross-sectional view showing a state where a switch of a conventional device is OFF.

FIG. 8 is a partial cross-sectional view showing a state where a switch of a conventional device is ON.

FIG. 9 is a partially enlarged cross-sectional view showing an inappropriate state for a conventional device.

FIG. 10 is a graph showing the relationship between the oil pressure of the device and the operation of the switch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc spring 2 Press-contact support part 3 Bottom wall part 4 Press part 5 Press-contact part 10 Vehicle equipment 12 Joint 13 Upper cover 15 Diaphragm 16 Diaphragm constituent member 18 O-ring 19 Welding part 20 Internal terminal 21 Connector 23 Caulking part 25 Working shaft 26 Elasticity Arm 27 Movable contact 35 Fixed contact 36 Connection terminal

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroyuki Furuya 1311 Aobadai, Tokorozawa-shi, Saitama F-term (reference) 5G052 AA02 AA03 BB10 HA02 HA06 HB01 HC10 5G056 DA01 DD36 DE02 DG02

Claims (3)

[Claims] 1. A conductive terminal for fixing a switch member having a movable contact is provided in a conductive joint fixed to a body, and a conductive disc spring which is always in contact with both the terminal and the joint is provided. A body earthing device for a switch, comprising: 2. The switch body grounding device according to claim 1, wherein a conductive sensor member is fixed in said joint, said disc spring is contracted between said sensor member and said terminal, and both are electrically connected. . 3. The disc spring according to claim 1, further comprising: a pressure contact supporting portion that presses against the inner periphery of the joint on the outer periphery; and a pressing portion that presses against the terminal on the inner peripheral side.
2. The body grounding device for a switch according to item 1.