JP3252364B2 - Push-push mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a push-push mechanism applied to a gas appliance operating device and the like.
A heart-shaped cam groove formed in one member that moves relatively, an engagement arm having one end engaged with the cam groove and the other end supported by the other member that moves relatively, and the engagement arm The present invention relates to a so-called heart cam type push / push mechanism, which comprises an urging means for urging one end of the arm to be pushed into the cam groove.

[0002]

2. Description of the Related Art Conventionally, as a push-push mechanism of this type, a biasing means is constituted by a ring-shaped spring formed by winding a single wire without connecting both ends thereof, and engaging the outer peripheral surface of the other member. A ring-shaped spring is provided in an engagement groove formed in a portion other than the joint arm arrangement portion so that a circumferential portion opposite to the portion where both ends of the spring are located projects to the engagement arm arrangement portion. Engage in a portion other than the circumferential portion in phase, inscribe an engagement arm in the circumferential portion,
There is known an apparatus in which an engagement arm is urged by a diameter reducing force of a ring-shaped spring. The ring-shaped spring is formed by winding the wire slightly less than two turns, and the bottom surface of the engaging groove is formed in a cylindrical surface having a diameter smaller than the inner diameter of the ring-shaped spring. The spring is slid on the bottom surface to reduce and expand the diameter.

[0003]

In the above-mentioned prior art, the ring-shaped spring may rotate in the circumferential direction, and both ends of the spring may protrude to the portion where the engagement arm is provided. There is a possibility that one end of the spring goes around the inside of the arm so as to sandwich the engagement arm with the first turn of the spring, and the engagement arm cannot be properly biased. Further, in the above-described conventional example, the ring-shaped spring is in point contact with the bottom surface of the engagement groove at each end, so that a twist is generated between the end of the spring and the bottom surface of the engagement groove, and the spring smoothly expands and contracts. Will not be
A twisting groove is formed on the bottom surface of the engaging groove by a terminal edge of the spring, and the terminal of the spring bites into the end of the twisting groove, so that the spring cannot be reduced in diameter. An object of the present invention is to provide a highly reliable push-push mechanism that has solved the above-mentioned problems.

[0004]

Means for Solving the Problems In order to solve the above problems,
According to the present invention, a heart-shaped cam groove formed in one member that moves relatively, an engagement arm having one end engaged with the cam groove and the other end supported by the other member that moves relatively, and an engagement arm And a biasing means for biasing the engagement arm so that one end of the engagement arm is pushed into the cam groove, wherein the biasing means is formed by winding one wire rod without connecting both ends. A ring-shaped spring is formed by turning the ring-shaped spring into an engagement groove formed on the outer peripheral surface of the other member other than the portion where the engagement arm is disposed, on the opposite side to the portion where both ends of the spring are located. In a portion other than the circumferential portion at a predetermined phase such that the circumferential portion of the engaging portion extends over the engaging arm arrangement portion, and the engaging arm is inscribed in the circumferential portion. At the end of the ring-shaped spring It provided with a stopper portion for detent the ring.

[0005] According to this, the ring-shaped spring is held in a predetermined phase, the engagement arm is appropriately biased, and a stable operation of the push-push mechanism is obtained. In the case where the ring-shaped spring is formed by winding the wire slightly less than one turn, when both ends of the spring protrude to the portion where the engagement arm is disposed, the engagement arm comes out of the spring through a gap between both ends of the spring. However, in the present invention, such a problem does not occur because the spring is prevented from rotating by the stopper portion. Therefore, as the ring-shaped spring, not only a conventional type in which the wire is slightly wound twice but also a wire in which the wire is slightly wound one turn can be used.

By the way, the ring-shaped spring is reduced in diameter when one end of the engagement arm is engaged with the deepest portion of the cam groove. And both ends of the spring abut against the stopper in a state where one end of the engaging arm is engaged with a portion shallower than the deepest portion of the cam groove due to the processing tolerance of the engaging arm and the like.
Since the further diameter reduction of the spring is restricted, the engagement arm may rattle without receiving the urging force from the spring at the deepest portion of the cam groove. In this case, in a state where one end of the engagement arm is engaged with the deepest portion of the cam groove and the diameter of the ring-shaped spring is reduced to the maximum, the stopper is moved between each end of the ring-shaped spring and the stopper. if a gap is formed in the empty memorial between, even if there is tolerance or the like, spring reliably reduced diameter to one end of the engagement arm engages the deepest portion of the cam groove, the deepest of the cam groove The engaging arm does not rattle at the portion.

In addition, if a base is provided on the bottom surface of the engaging groove so as to be in line contact with the vicinity of each end of the ring-shaped spring, the base near the end of the spring is expanded when the spring is expanded or contracted. Is slid on the outer peripheral surface without twisting, and the spring is smoothly expanded and contracted. In this case, if a relief portion is formed on the outer peripheral surface of the base portion in the vicinity of the stopper portion to secure a radial gap between each end of the ring-shaped spring, the base portion is formed. The outer peripheral surface is not formed with a twist groove due to the end edge of the spring, and the end of the spring does not bite into the end of the twist groove so that the spring cannot be reduced in diameter.

In some cases, a twisting groove formed by a terminal edge of a spring is formed on the groove wall of the engaging groove. To prevent this, a groove is provided near the stopper on the groove wall of the engaging groove. In addition, it is desirable to form a clearance between each end of the ring-shaped spring and a clearance in the groove width direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, reference numeral 1 denotes a water heater main body composed of a back plate 1a and a front cover 1b. The main body 1 includes a gas burner 2 and the burner. And a heat exchanger 3 using 2 as a heat source.
A water valve unit 5 connected to the lower water pipe joint 4 and a gas valve unit 7 connected to the lower gas pipe joint 6 are provided.

A heat exchange water passage 8 and a bypass water passage 9 passing through the heat exchanger 3 are connected to the downstream side of the water system valve unit 5, and a downstream end of the heat exchange water passage 8 and a downstream end of the bypass water passage 9 are connected to each other. Mixing unit 1 provided at the center of the lower end of water heater body 1
At 0, the tapping head 11 was connected to the mixing section 10 via a flexible tube 12.

As shown schematically in FIG. 3, the gas system valve unit 7 includes, in order from the upstream side, a safety valve 70 composed of an electromagnetic valve, a water pressure responsive valve 71, a gas governor 72, and a gas amount regulating valve 73. Are provided.

As shown in FIG. 4, the water-based valve unit 5 includes a water stop valve 50 and a water governor 5 in order from the upstream side.
1 and a water amount adjusting valve 52 are provided. Water stop valve 50
Is the valve chamber 5 of the water stop valve 50 connected to the water pipe joint 4.
A diaphragm valve 50c for closing a valve hole 50b formed in a partition member 53 defining the water governor 0a and the water governor 51, and a bypass valve 50e provided in a back pressure chamber 50d defined by the diaphragm valve 50c. Diaphragm valve 50c
An orifice hole 50f communicating the valve chamber 50a with the back pressure chamber 50d and a bypass hole 50g communicating the back pressure chamber 50d with the water governor 51 are formed.
The pressure is applied to the diaphragm valve 50c side at h, so that the bypass valve 50e normally closes the bypass hole 50g. Then, when the bypass valve 50e is retracted against the spring 50h to open the bypass hole 50g, the pressure in the back pressure chamber 50d decreases, and the diaphragm valve 50c retracts due to the pressure difference with the valve chamber 50a. The valve hole 50b is opened,
Water was passed through the water governor 51.

The water governor 51 includes a valve body 5 inserted in a valve seat member 51c defining a primary pressure chamber 51a and a secondary pressure chamber 51b.
1d and a diaphragm 51e on the side of the secondary pressure chamber 51b connecting the valve element 51d, and a venturi 55 provided with a back pressure chamber 51f defined by the diaphragm 51e at an outlet 54 for a heat exchange water passage. Communication hole 5 in the negative pressure outlet 55a
5b, the diaphragm 51e bends toward the back pressure chamber 51f side due to the negative pressure generated in the venturi 55 when water is passed through the water stop valve 50 to open.
The hydraulic pressure responsive valve 71 is opened via a rod 51g interlocked with.

The water amount adjusting valve 52 has a cylindrical valve body 52b rotatably mounted in a cylindrical valve chamber 52a communicating with the water governor 51 on the back side of the drawing of FIG. ,
As shown in FIG. 5, the valve hole 5 facing the outlet section 54 for the heat exchange waterway is provided.
2c and the valve hole 52d facing the outlet 56 for the bypass waterway
And the amount of water flow to the heat exchange water passage 8 and the bypass water passage 9 can be increased or decreased by the rotation of the valve body 52b.

The gas regulating valve 73 is operated by a lever 13 shown in FIG. 1 via a pinion 15 which meshes with a fan-shaped rack 14 at the upper end thereof. The water stop valve 50 and the water regulating valve 52 are a single unit. Operated by the operation knob 16,
Hereinafter, operation devices of the water stop valve 50 and the water amount adjustment valve 52 will be described in detail.

The water-based valve unit 5 includes a water amount adjusting valve 52.
The shaft 52e of the valve body 52b faces forward, and the operating rod 50i connected to the pilot valve 50e of the water stop valve 50 is arranged to face outward in the lateral direction, as shown in FIGS. 5 and 6. The operating device is mounted on a U-shaped mounting bracket 17 fixed to the front of the water-based valve unit 5.

As shown in FIG. 7, the operation device includes an operation knob 1
6, a base plate 18 screwed to the front end of the mounting bracket 17, a rotating member 19 held on the base plate 18 so as to be rotatable around an axis in the front-rear direction, A reciprocating member 20 that is freely held, and a slider 21 that slidably engages with the rotating member 19 in the front-rear direction.
And a lever 22 pivotally attached to the mounting bracket 17.

The rotating member 19 includes a cylindrical portion 19a rotatably fitted in a circular hole 18a formed in the base board 18, and claw portions 19b formed at a plurality of locations around the front end of the cylindrical portion 19a.
And a flange portion 19c at the rear end of the cylindrical portion 19a. When the cylindrical portion 19a is fitted inside the circular hole 18a,
The claw portion 19b engages with the front edge of the circular hole 18a, and the flange portion 19c abuts against the back surface of the base board 18, so that the rotating member 19 is prevented from coming off from the base board 18. The rear portion of the rotating member 19 is formed in a bottomed square tube portion 19d, and the slider 21 formed in a square tube shape is attached to the square tube portion 19d.
d with the spring 21a interposed between it and the rear end.
9d, and thus the slider 21 was stopped against the rotating member 19 and engaged slidably in the front-rear direction.

The reciprocating member 20 is formed in a cylindrical shape surrounding the rectangular tube portion 19d, and a pair of guide sleeves 20a, 20a extending forward are integrally formed at two locations around the outer periphery thereof. The sleeves 20a, 20a are
Can be externally inserted into a pair of rearwardly extending guide bars 18b, 18b integrally protruding from the back surface of the base plate 18 so that the reciprocating member 20 can be supported against the base board 18 so as to be reciprocally movable in the front-rear direction. I did it. A flange portion 20b is formed at the front end of the reciprocating member 20, and the slider 21
A claw portion 21b is formed on the rotating member 19 and protrudes outward through a slit groove 19e extending in the front-rear direction, and the claw portion 21b is engaged with the flange portion 20b. And the reciprocating member 20 can be connected in the front-rear direction while allowing the relative rotation of the slider 21. A heart cam type push / push mechanism 23, which will be described in detail later, is provided between the rotating member 19 and the slider 21.

When assembling the operating device, the rotating member 19
After inserting the slider 21 into the push-push mechanism 2
Then, the slider 21 and the reciprocating member 20 are connected by engaging the claw 21b with the flange 20b.
At the time of this connection, the notch 20c of the flange portion 20b
The phase of the reciprocating member 20 is extrapolated to the rotating member 19 with the phase adjusted to match the claw portion 21b.
Is rotated to engage the flange portion 20b with the claw portion 21b.

Thus, the rotating member 19 and the slider 2
1 and after the push-push mechanism 23 and a reciprocating member 20 and Sabuasse down Buri, assembling the sub-assembly body to the base plate 18. When assembling, the cylindrical part 1
9a is fitted inside the circular hole 18a and the guide sleeve 20a is fitted outside the guide bar 18b. A pair of receiving portions 18c, 18 protruding from the rear surface of the base
8, the rotation range of the rotation member 19 is restricted as shown in FIG. 8, and the claw portion 21b of the slider 21 which is prevented from rotating by the rotation member 19 matches the notch 20c of the flange portion 20b of the reciprocating member 20. The slider 21 and the reciprocating member 20 are not disconnected.

A pair of guide bars 19g, 19g projecting forward from the cylindrical portion 19a is provided on the rotating member 19, and a shaft 21c extending forward is provided on the slider 21. A central boss hole 16a and a pair of boss holes 16b, 16b on both sides thereof are formed in the inner surface of the knob 16, and both guide bars 19g, 19g are slidably inserted into both boss holes 16b, 16b. Shaft portion 21c in hole 16a
So that the operation knob 16 is prevented from rotating with respect to the rotating member 19 so that the operation knob 16 can be relatively movably engaged in the front-rear direction, and the slider 21 is pressed by the operation knob 16.
Was moved backwards.

After assembling the operating device as described above, the base plate 18 is screwed to the mounting bracket 17. According to this, the rotating member 19 is disposed coaxially with the water flow regulating valve 52 in front. Will be. At the rear end of the rotating member 19, a shaft portion 19h of a modified cross section extending rearward is protruded, and as shown in FIG. The shaft portion 19h is fitted, and the rotating member 19 and the valve body 52b of the water amount adjustment valve 52 are directly connected.

A protrusion 20d projecting from the rear end of the reciprocating member 20 abuts one end of the lever 22, and the reciprocating member 20
The water stop valve 50 is opened via the lever 22 in the forward movement of the rear. The lever 22 is constituted by an L-shaped lever having an intermediate portion pivotally supported by the mounting bracket 17 via a pivot 22a, and the other end of the lever 22 is connected to the bypass valve 50 of the water stop valve 50.
e, a piece 5 at the outer end of the valve rod 50i connected as shown in FIG.
When the lever 22 is pivoted in the counterclockwise direction in FIG. 6 by the backward movement of the reciprocating member 20, the bypass valve 50e is pulled open against the spring 50h and the water stop valve is engaged. 50
Was opened. The lever 22 is a spring 22b.
Thus, the water shutoff valve 50 is urged in the closing direction, that is, clockwise in FIG. In the figure, reference numeral 22c denotes a guide bar 18b and a guide sleeve 20a formed at one end of the lever 22.
The escape hole for

The base board 18 is provided with a first switch SW1 linked to a rotating member 19 and a second switch SW2 linked to a reciprocating member 20. The first switch SW1 functions as a power switch of the combustion control circuit. As shown in FIG. 8, when the switch lever SW1a is pushed up by the flange portion 19c of the rotating member 19, the first switch SW1 is turned on, and the rotating member 19 is stopped. When 19f is turned to one of the turning end positions where it comes into contact with the receiving portion 18c,
The first switch SW1 is to be turned off depressed switch lever SW1a the notch portions 19 k of the flange portion 19c.

The second switch SW2 functions as an ignition switch. As shown in FIG. 9, the second switch SW2 includes a switch lever SW2a cooperating with a cam projection 20e formed on one guide sleeve 20a of the reciprocating member 20. The switch is turned on when the switch lever SW2a is pushed up by the cam projection 20e in the backward movement of the reciprocating member 20.

Further, as shown in FIG. 3, a third switch SW3 is provided in conjunction with the hydraulic pressure responsive valve 71. The third switch SW3 functions as a valve opening switch for the safety valve 70. The third switch SW3 cooperates with a piece 71a at the outer end of the water pressure responsive valve 71 to which the rod 51g of the water governor 51 abuts to open the water pressure responsive valve 71. Sometimes turned on.

When the second switch SW2 and the third switch SW3 are turned on while the first switch SW1 is turned on, the safety valve 70 is opened and the igniter 24 attached to the gas burner 2 (see FIG. 1). Operates and gas burner 2
Is ignited. After the ignition, the safety valve 70 is kept open by a signal from the frame rod 25 attached to the gas burner 2 for a certain period, and then the safety valve 70 is kept open by the output of the thermocouple 26 for flame detection. The thermocouple 26 is connected to a thermocouple 27 for detecting oxygen deficiency attached to the heat exchanger 3 with an opposite polarity, and the output of the thermocouple 26 is canceled by the output of the thermocouple 27 when oxygen is deficient. The safety valve 70 closes.

With the first switch SW1 turned off, the safety valve 70 is not opened and the igniter 24 is not operated even if both the second and third switches SW2 and SW3 are turned on. The turning position where the first switch SW1 is turned off is set as the water position of the operation knob 16.

Thus, when the operation knob 16 is pushed at a rotational position other than the water position, the reciprocating member 20 is moved backward through the slider 21 to turn on the second switch SW2. The water stop valve 50 is opened via the lever 22 and water is passed through the heat exchanger 3. Then, by this water flow, the water pressure responsive valve 7 is connected via the rod 51g of the water governor 51.
1 is opened and the third switch SW3 is turned on,
The safety valve 70 is opened and the igniter 24 is operated to ignite the gas burner 2 and discharge hot water. afterwards,
Even if the pressing of the operation knob 16 is released, the reciprocating member 20 is locked at the forward movement position via the slider 21 by the push-push mechanism 23, and the hot water is continuously discharged.

When the operation knob 16 is rotated, the rotation member 19 is rotated.
, The valve body 52b of the water amount adjustment valve 52 is rotated, the amount of water flowing to the heat exchanger 3 is increased or decreased, and the outlet temperature changes.
Thus, the tapping temperature can be adjusted by turning the operation knob 16, but when the operation knob 16 is turned to the water position, the first switch SW1 is turned off, the safety valve 70 is closed, and the combustion of the gas burner 2 is stopped. Then, unheated water is discharged.
It should be noted that water is also discharged when the operation knob 16 is set to the water position and pressed from the beginning.

As shown in FIGS. 7 and 10, the push-push mechanism 23 includes a heart-shaped cam groove 230 formed on one side of the slider 21 and one side of the square tubular portion 19d of the rotating member 19 at one end. A substantially U-shaped engagement arm 231 is engaged with the cam groove 230 through a slit 19i formed at the other end thereof, and the other end is inserted and supported in a groove 19j formed at the rear end surface of the rotating member 19, One end is cam groove 2
And a ring-shaped spring 232 that urges inward so as to be pushed into the thirty.

As shown in FIG. 11, the cam groove 230 includes a portion a at the rear end, a portion b at one front end in the groove width direction, a portion d at the other front end in the groove width direction, and a portion b and d. C recessed backward in the middle
And one end of the engagement arm 231 shifts from the portion a to the portion b by the first push operation of the operation knob 16, and shifts from the portion b to the portion c by release of the push operation to reciprocate. Member 2
0 is locked at the forward movement position, one end of the engagement arm 231 is moved from the part c to the part a via the part d by the second push operation of the operation knob 16 and the release thereof, and the reciprocating member 20 is moved backward. Return to position.

The cam groove 230 is provided with a step as shown in FIG. 12 so that one end of the engaging arm 231 does not move in the opposite direction to the above. Is deepest in the portions a and d.

The reciprocating member 20 is moved back to a position where one end of the engaging arm 231 is in contact with the rear end of the portion a of the cam groove 230, and the reciprocating member 20 is pushed when the operation knob 16 is pushed. The forward end position may be regulated by abutting the front end of the portion b or the front end of the d portion of the cam groove 230 with one end of the engagement arm 231. However, in this case, a large impact acts on one end of the engagement arm 231. I do. Therefore, in the present embodiment, the reciprocating position of the reciprocating member 20 is set to the sleeve 20 to the base plate 18.
a, and the forward end position of the reciprocating member 20 is regulated by the abutment of the operation knob 16 on the base board 18. , B
The part and the front end of the part d do not abut. According to this, durability can be ensured even if the diameter of the engagement arm 231 is reduced, and the stroke of the push-push mechanism 23 can be reduced by reducing the diameter.

The rear end of the rotating member 19 is
1 is formed in a substantially D-shaped cross section in which one side as an arrangement portion is a flat surface, and the remaining outer peripheral surface is a cylindrical surface having a smaller diameter than the ring-shaped spring 232, and is formed between the rear end portion and the square cylindrical portion 19d. A circular flange 233a is protruded from one of the outer peripheral surfaces except for one side surface, and claw portions 233b are protruded from three peripheral portions of the cylindrical portion on the outer peripheral surface at the rear end as shown in FIG.
An engagement groove 233 for a spring was formed between 33a and the claw portion 233b.

The ring-shaped spring 232 is formed by winding a single wire, such as a piano wire, slightly less than one end without connecting both ends. Is engaged with the engaging groove 233 in a portion other than the circumferential portion at a predetermined phase such that the circumferential portion of the The arm 231 was inscribed.

A stopper 233c is provided on the bottom surface of the engaging groove 233, which is located on the opposite side to the one side surface, and is inserted into the abutment portion of the ring-shaped spring 232 so as to protrude therefrom.
Each end of the spring 232 comes into contact with the stopper 233c, so that the spring 232 is prevented from rotating.

The ring-shaped spring 232 is formed such that one end of the engagement arm 231 is connected to the deepest portion a or d of the cam groove 230.
The diameter of the ring-shaped spring 232 is reduced when it is engaged with the stopper portion.
It is also conceivable to form the stopper portion 233c so as to abut the 33c. However, in this case, the engagement arm 231
The ring-shaped spring 2 necessary for circumscribing the engagement arm 231 with one end of the
32 becomes smaller than a normal value due to processing tolerances of the cam groove 230 and the engagement arm 231, wear of the groove bottom of the cam groove 230, etc. The ends of the ring-shaped spring 232 abut on the stopper 233c while one end of the ring-shaped spring 232 is engaged. When hiding, the ring-shaped spring 232
Cannot be further reduced, and when one end of the engagement arm 231 is engaged with the deepest portion of the cam groove 230, the engagement arm 2
31 and to have an empty gap between the ring-shaped spring 232, the engaging arm 231 will be attached backlash, the cam groove 23
0 may cause the engagement arm 231 to move backwards.

[0040] Therefore, in this embodiment, the stopper portion 233c in the gap is empty memorial between each terminal of the stopper portion 233c and the ring-shaped spring 232 in a state where the ring-shaped spring 232 is reduced in diameter to the normal value Even if there is a processing tolerance or the like, one end of the engagement arm 231 is
At the deepest part of the cylinder 0, the ring-shaped spring 232 receives the contracting force of the ring-shaped spring 232 so as to be engaged without play.

The ring-shaped spring 23 is located on the bottom of the engagement groove 233 on both sides of the stopper portion 233c.
2, a base 233d having an arc-shaped outer peripheral surface in line contact with the vicinity of each terminal is protruded, and the ring-shaped spring 232 slides on the base 233d in the vicinity of the terminal without twisting, The spring 232 is smoothly expanded and contracted.

Further, the ring-shaped spring 2 is positioned on the outer peripheral surface of the base 233d near the stopper 233c.
Escape part 2 for securing a radial gap between each terminal 32
33e was formed. According to this, the torsion groove is not carved by the terminal edge of the ring-shaped spring 232 on the outer peripheral surface of the base portion 233d, and the spring 232 is contracted by the terminal of the ring-shaped spring 232 biting into the end of the torsion groove. The occurrence of a failure such as an inability to make a diameter is prevented, and the durability of the push-push mechanism 23 is improved.
In the present embodiment, since the gap is have empty between each terminal and the stopper portion 233c of the spring 232 at the outermost diameter-state of the ring-shaped spring 232, the ring-shaped spring 232 can this gap min rotation is there. And
One end of the ring-shaped spring 232 is the stopper 2
When the diameter of the spring 232 expands in a state in which the spring 232 is in contact with the spring 33c, the other end of the spring 232 is
However, when the diameter of the ring-shaped spring 232 is expanded, a force acting to lift the end of the spring 232 radially outward with the circumferential outer end of the base 233d acting as a fulcrum acts. So, the ring spring 2
Twisting of the outer peripheral surface of the base 233d due to the 32 terminal edges does not occur.

Further, if used for a long period of time, the groove wall of the engagement groove 233 may be formed with a twisting groove by the end edge of the ring-shaped spring 232, and the spring 232 may not be able to be reduced in diameter. Therefore, in the present embodiment, as shown in FIG. 14, the flange 233a serving as the groove wall and the claw portion 233b are provided.
An escape portion 233f is formed near the stopper portion 233c to secure a gap in the groove width direction between each end of the ring-shaped spring 232 so as to prevent a prying groove from being formed in the groove wall. did.

One end of the engagement arm 231 is
When the engagement arm 231 is engaged with a shallow portion of the engagement arm 231, the engagement arm 231 tilts upward and the portion of the ring-shaped spring 232 on the engagement arm 231 side is a pair of claw portions 233 b, 233 b near the arrangement portion of the engagement arm 231. 13 to the back (the back side of the paper surface of FIG. 13). If the bending stiffness against this deflection is too strong, the operation load becomes heavy, and if it is too weak, the engaging arm 231 is formed.
May remain tilted forward, causing the engagement arm 231 to move backward with respect to the cam groove 230. Therefore, the engaging arm 2 is required to obtain the required bending rigidity.
It is necessary to appropriately set the position of the claw portion 233b near the disposition portion 31.

In the above-described embodiment, the groove wall on the rear side of the engagement groove 233 is divided into three by the three claw portions 233b, but a pair of claw portions near the arrangement portion of the engagement arm 231 are formed. 23
The groove wall on the rear side of the engaging groove 233 may be formed by a continuous flange having both ends at positions 3b and 233b. The general portion (except for the stopper portion 233c and the base portion 233d) of the bottom surface of the engagement groove 233 is formed in a cylindrical surface having a smaller diameter than the ring-shaped spring 232, but has the same rectangular cylindrical surface as the rectangular cylindrical portion 19d. May be formed. Further, in the above embodiment, the rotating member 19 and the slider 21 which are two members that move relatively
Of these, the cam groove 230 is formed in the slider 21, but the cam groove 230 is formed in
The slider 31 and the ring-shaped spring 232 may be supported by the slider 21.

In the above embodiment, the ring-shaped spring 232 is formed by winding the wire slightly less than one turn, but the ring-shaped spring 232 may be formed by winding the wire slightly less than two turns. As shown in FIGS. 15 and 16,
The stopper portions 233c are provided separately before and after the first turn of the ring-shaped spring 232, and each end of the spring 232 is configured to abut on each different stopper portion 233c. The other configuration is not particularly different from the above embodiment, and the same members as those described above are denoted by the same reference numerals as those described above, and description thereof will be omitted.

Although the embodiment in which the present invention is applied to the push-push mechanism incorporated in the operating device of the water heater has been described above, the present invention is similarly applied to the push-push mechanism incorporated in the operating device of equipment other than the water heater. Applicable.

[0048]

As is apparent from the above description, according to the present invention, the ring-shaped spring can be held at a predetermined phase and the engaging arm can be properly biased. Is obtained, and not only a two-turn type but also a one-turn type can be used as the ring-shaped spring, which increases the degree of freedom in design. In addition, by projecting the base portion in the spring engagement groove, the ring-shaped spring is smoothly expanded and contracted, the operation of the push-push mechanism is further stabilized, and the escape portion is provided in the base portion and the groove wall. Thus, the formation of a twisting groove due to the end edge of the ring-shaped spring can be prevented, and the durability of the push-push mechanism is improved.

[Brief description of the drawings]

FIG. 1 is a front view of a water heater having an operating device incorporating a push-push mechanism of the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is a diagram schematically showing a gas valve unit of a water heater.

FIG. 4 is a cutaway front view of a water-based valve unit of a water heater.

FIG. 5 is a side view of the water-based valve unit in a state where the operation device is assembled.

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5;

FIG. 7 is an exploded perspective view of the operation device.

FIG. 8 is a diagram illustrating the on / off operation of a first switch.

FIG. 9 is a diagram illustrating the on / off operation of a second switch.

FIG. 10 is a cut-away plan view of a push-push mechanism part.

FIG. 11 is a front view of a cam groove.

FIG. 12 is an expanded sectional view of a cam groove.

13 is a sectional view taken along line XIII-XIII of FIG.

14 is an unfolded side view as viewed from the arrow XIV in FIG.

FIG. 15 is a cross-sectional view corresponding to FIG. 13 of another embodiment.

16 is an unfolded side view as viewed from the arrow XVI in FIG.

[Explanation of symbols]

Reference Signs List 19 rotation member (the other member) 21 slider (one member) 23 push-push mechanism 230 cam groove 231 engagement arm 232 ring-shaped spring 233 engagement groove 233c stopper part 233d base part 233e relief part (radial direction) 233f relief Part (groove width direction)

Continuation of the front page (56) References JP-A-61-208435 (JP, A) JP-A 50-144263 (JP, U) JP-A 57-14331 (JP, U) JP-A 57-58233 (JP, U.S.A.) , U) Fully open 1983-58944 (JP, U) Fully open 1984-28932 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G05G 1 / 02,5 / 00 F16F 1/02 F23N 5/26 H01H 13/56

Claims (5)

(57) [Claims] An engagement arm having one end engaged with the cam groove and one end engaged with the cam groove and the other end supported by the other relatively movable member; And a biasing means for biasing the arm so that one end of the engaging arm is pushed into the cam groove. A ring-shaped spring is formed by winding the ring-shaped spring into an engagement groove formed on the outer peripheral surface of the other member other than the portion where the engagement arm is disposed. The engagement is performed in a portion other than the circumferential portion with a predetermined phase such that the circumferential portion on the side protrudes to the arrangement portion of the engaging arm, and the engaging arm is inscribed in the circumferential portion. In contact with each end of the ring-shaped spring, A push-push mechanism characterized by providing a stopper for stopping the pulling. 2. The end portion of the ring spring and the stopper portion when the one end of the engagement arm is engaged with the deepest portion of the cam groove and the diameter of the ring spring is reduced most. push-push mechanism according to claim 1, characterized in that a gap is formed in the empty memorial between. 3. The push-push mechanism according to claim 1, wherein a base portion that comes into line contact with a portion near each end of the ring-shaped spring is projected from a bottom surface of the engagement groove. 4. A relief portion is formed on the outer peripheral surface of the base portion near the stopper portion to secure a radial gap between each end of the ring-shaped spring. The push-push mechanism according to claim 3. 5. A relief portion is formed on a groove wall of the engagement groove in the vicinity of the stopper portion to secure a clearance in a groove width direction between each end of the ring-shaped spring. The push-push mechanism according to any one of claims 1 to 4, wherein: