JP4003390B2 - Key switch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a key switch used as, for example, a door safety switch.
[0002]
[Prior art]
A door safety switch is attached to a safety door of a mechanical device or a door of a protective fence in order to prevent an accident caused by an inadvertent operation or an accidental operation in various machine tools and industrial machine devices.
[0003]
This type of safety switch must be configured so that it cannot be operated with a tool other than a dedicated key (for example, a screwdriver), and the internal device is locked in the initial state where the key is removed. An example of this is shown in FIGS.
[0004]
This key switch rotates the cam plate 104 in accordance with the insertion / extraction of the key 103 into / from the key insertion port 102 formed in the switch case 101, and moves the plunger 105 that abuts against the outer peripheral cam surface of the cam plate 104. A rotation locking mechanism 106 is configured to switch a switching mechanism (not shown) by being displaced in conjunction with the rotation of the plate 104 and to prevent the cam plate 104 from rotating in the initial state where the key 103 is extracted. It has.
[0005]
The rotation lock mechanism 106 includes a pair of front and rear lock members 107 disposed near the outer periphery of the cam plate 104 so as to be able to advance and retreat in the direction of the rotation axis q of the cam plate 104, and press them toward the cam plate 104. A lock pin 109, which is formed of a spring 108 that protrudes from the lock member 107, is urged into an engagement recess 110 formed on the outer periphery of the cam plate 104, thereby fixing the cam plate 104 to an initial state. It is configured.
[0006]
Each lock member 107 is formed with an unlocking cam inclined surface 111 directed toward the key insertion slot 102. As shown in FIG. 18, each lock member 107 is formed at the tip of the key 103 inserted into the key insertion slot 102. The lock release cam slope 111 is pressed and the lock members 107 are moved backwardly against the springs 108 to release the locks. As shown in FIG. The plate 104 is rotated.
[0007]
[Problems to be solved by the invention]
According to the rotation lock mechanism 106 configured as described above, the lock member 107 is disposed so as to be able to advance and retreat in the direction of the rotation axis q of the cam plate 104, so that the space for arranging the lock member 107 and the lock biasing spring 108 is small. The cam plate 104 is large in the direction of the rotation axis q, and the thickness of the entire switch in the longitudinal direction is inevitably large.
[0008]
Further, according to the standard, since a pair of the lock members 107 are provided before and after the cam plate 104, the space in the front-rear direction of the rotation lock mechanism 106 is further increased, leading to an increase in the size of the key switch.
[0009]
As described above, such a key switch is used as a door safety switch for preventing accidents due to careless operations or accidental operations in various machine tools and industrial machine devices. Even if the user uses the product slightly out of the normal usage state, or when the wear of parts occurs due to long-term use, the function is achieved to prevent accidents in advance. It is necessary to secure.
[0010]
The present invention has been made paying attention to such points, and by improving the rotation lock mechanism, the entire switch can be made thin, and regardless of the use state of the key switch, An object of the present invention is to provide a highly reliable key switch that suppresses erroneous rotation of a cam member by a key even if wear or the like occurs due to use.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured as follows.
[0017]
The key switch of the present invention rotates the cam member in accordance with the insertion / extraction of the key into / from the key insertion port, and displaces the plunger that contacts the outer peripheral cam surface of the cam member in conjunction with the rotation of the cam member. A key switch provided with a rotation lock mechanism for preventing the cam member from rotating in a key-extracted state, wherein the switch member is supported by the rotation lock mechanism. A lock member that is displaceable in a direction parallel to a rotation surface that is perpendicular to the shaft, and a spring that biases the lock member toward a lock position that engages the cam member. The cam member can be displaced to the unlocking position against the spring by abutting with the cam, and a cam portion for switching off acting on the plunger and a switch acting on the plunger are provided on the outer peripheral surface of the cam member. And a cam member for controlling the cam member to be switched off when the cam member is erroneously rotated, while the cam member is A lock groove that engages with the lock member and restricts the rotation of the cam member is formed.
[0018]
According to the present invention, if wear of parts occurs, the key may slip out and be pulled out without the cam member being sufficiently rotated. If the key is inserted again without noticing this, the cam member will be greatly mistaken. It will be turned. In this case, the check cam portion acts to bring about a switch-off state, and the rotation of the cam member is restricted by the engagement with the lock member, so that the key is inserted / removed in the erroneously rotated state. However, the cam member does not rotate further erroneously.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, some embodiments of the present invention will be described with reference to the drawings.
[0023]
(Embodiment 1)
1 to 12 show a first embodiment of a key switch according to the present invention. FIG. 1 is a perspective view showing the overall appearance of the key switch, and FIG. 2 is a longitudinal sectional view thereof.
[0024]
The switch case 1 of this key switch is composed of a main body case 1A and a head case 1B connected to the upper end thereof. The main body case 1A accommodates a switch mechanism 2 and a plunger 3 for switching the head mechanism 1A. In the case 1B, a cam plate 4 as a cam member acting on the upper end of the plunger 3 is accommodated so as to be rotatable around a horizontal axis p in the horizontal direction shown in FIGS. 4 and 5, and the upper side of the head case 1B. The key 6 is inserted into and removed from the key insertion opening 5 formed on the side surface, the cam plate 4 is rotated, and the plunger 3 that abuts on the outer peripheral cam surface is displaced up and down to perform the contact switching operation of the switch mechanism 2. It is configured as follows.
[0025]
As shown in FIG. 2, a holder 7 is incorporated in the main body case 1A. The holder 7 is equipped with a switch mechanism 2, and the plunger 3 can be slid up and down, and the upper surface of the main body case 1A can be slid. It is supported to leave the center. The switch mechanism 2 includes three sets of fixed terminals 8, 9, 10 that are driven into and fixed to the holder 7, and three sets of movable terminals 11, 12, 13 that are mounted on the plunger 3 so as to be elastically displaceable. The lead wires of the electric wires inserted from the lower end of the main body case 1A are connected to the fixed terminals 8, 9, and 10. In the initial state where the key 6 is extracted, as shown in FIG. 2, the plunger 3 is pushed and displaced against a return spring (not shown). In this initial state, the movable terminals 11 and 12 are fixed terminals. 8 and 9, the conduction between the fixed terminals 8 and 9 is interrupted, and the movable terminal 13 is brought into contact with the fixed terminal 10, so that the fixed terminals 10 are connected. That is, in this case, the fixed terminals 8 and 9 are used as normally open terminals, and the fixed terminal 10 is used as a normally closed terminal.
[0026]
As shown in FIGS. 3 and 4, a fulcrum bracket 20 is incorporated in the head case 1 </ b> B, and the head case 1 </ b> B is supported across a pair of left and right shaft support walls 20 a erected on the fulcrum bracket 20 and the center of the cam plate 4. The shaft 21 is inserted, and the cam plate 4 is rotatably supported around the horizontal axis p in the head case 1B. The outer peripheral surface of the cam plate 4 is a cam surface that abuts on the upper end of the plunger 3, and a switch-off operation cam portion 22 that presses the upper end of the plunger 3 at a predetermined position in the circumferential direction; A switch-on operation cam portion 23 for releasing the pushing of the plunger 3 and a check cam portion 24 for preventing malfunction are formed. On the outer peripheral surface of the cam plate 4, a switch-on operation protrusion 25 that is pressed by the tip of the inserted key 6 and a switch-off operation engagement protrusion 26 that is engaged with the key 6 that is pulled out. Is provided.
[0027]
As shown in FIG. 2, in the initial state where the key 6 is extracted, when the plunger 3 is pushed by the cam portion 22 and the key 6 is inserted from the key insertion port 5 on the side surface, the switch-on operation is performed. When the projection 25 is contacted and pressed at the tip of the key 6, the cam plate 4 is rotated counterclockwise (switch-on direction) in the figure, and the upper end of the plunger 3 is the cam portion 23 of the cam plate 4. Accordingly, the plunger 3 projects upward by the return biasing force, and the switch mechanism 2 is switched (switch-on).
[0028]
In the key switch configured as described above, in the initial state in which the key 6 is extracted, the cam plate 4 is prevented from being rotated by inserting anything other than a dedicated key into the key insertion slot 5. In order to make the cam plate 4 in the initial state unrotatable, a rotation lock mechanism 30 is provided in the head case 1B as shown in FIGS.
[0029]
The rotation lock mechanism 30 includes a pair of front and rear lock members 31 that act on the front and rear side surfaces of the cam plate 4. The lock member 31 is supported so as to be linearly slidable in the direction of 45 ° obliquely along a guide groove 32 formed on the outer surface of each of the front and rear shaft support walls 20a of the fulcrum bracket 20 and supports the cam plate 4 in a penetrating manner. Both end portions of the support shaft 21 are inserted into a long hole 33 formed in the lock member 31.
[0030]
In addition, a rectangular lock pin 34 is provided on the inner surface of the lock member 31, and the lock pin 34 projects toward the cam plate 4 through the shaft support wall 20a. On the other hand, on the front and back side surfaces of the cam plate 4, a locking recess 35 for engaging the lock pin 34 is formed. As shown in FIG. 5, a lock groove 35a that extends radially outward is continuously provided in the lock recess 35, and the lock member 31 slides obliquely upward, so that the lock pin 34 becomes the lock groove 35a. When engaged, a locked state is generated in which the rotation of the cam plate 4 is prevented. When the lock member 31 slides obliquely downward and the lock pin 34 is disengaged from the lock groove 35a, the cam plate 4 rotates. An unlocked state that allows movement is provided.
[0031]
Further, the locking recess 35 is provided with a locking groove 35b for preventing the malfunction by restricting the rotation range of the cam plate 4 together with the above-described check cam portion 24 for preventing the malfunction. .
[0032]
Further, as shown in FIG. 3, a spring 36 is assembled between the lower end portion of the lock member 31 and the bottom portion of the guide groove 32, and the lock member 31 is slid and biased toward the lock position obliquely upward. Yes.
[0033]
The rotation lock mechanism 30 of this example is configured as described above, and in the initial state where the key is removed, the lock member 31 is slid and biased to the lock position obliquely upward to prevent the cam plate 4 from rotating. As shown below, the key 6 is properly inserted into the key insertion opening 5 on the side surface of the case, so that the lock member 31 is brought into contact with and moved to the unlocking position obliquely downward against the spring 36, and continues. The cam plate 4 is rotated by inserting the key.
[0034]
Next, the operation of the rotation lock mechanism 30 when the switch switching operation is performed by inserting and removing the key 6 from the side surface will be described with reference to FIGS.
[0035]
(1) When the regular key 6 is inserted into the key insertion slot 5 on the lateral side, first, the distal end portion of the operation rib 6a projecting on both sides of the lower surface of the key 6 comes into contact with the upper end of the lock member 31 at the lock position. When the key 6 is pushed in until the tip of the key 6 comes into contact with the switch-on operation projection 25 of the cam plate 4, the lock member 31 resists the spring 36 by the lower end surface of the operation rib 6a as shown in FIG. Thus, the cam plate 4 is forcibly retracted downward and released from the lock groove 35a, so that the cam plate 4 is unlocked so that it can be rotated counterclockwise. Note that a guide 37 that slides and guides the upper surface of the inserted key 6 is provided on the inner surface of the ceiling of the head case 1B, and the key 6 is prevented from escaping upward by the pressing reaction force of the lock member 31. ing.
[0036]
(2) When the key 6 is subsequently pushed in, as shown in FIG. 7, the tip of the key 6 contacts and presses the switch-on operation protrusion 25 of the cam plate 4, and the cam plate 4 rotates counterclockwise. It will be done. In this case, when the cam plate 4 is rotated counterclockwise, the lock member 31 is disengaged from the operation rib 6 a of the key 6, but the lock pin 34 is relatively pressed by the inner peripheral surface of the lock recess 35. Thus, it is moved backward to the axis p side.
[0037]
When the key 6 is further pushed in, the plunger 3 is detached from the cam portion 22, and the cam plate 4 is pressed and rotated counterclockwise by the protruding biasing force of the plunger 3, so that the plunger 3 moves to the cam portion 23 as shown in FIG. 8. Engages stably at the bottom, resulting in a switch-on state. In this case, the engagement protrusion 26 for switch-off operation and the operation hole 6b formed in the key 6 are engaged.
[0038]
(3) When the key 6 is pulled out from the switch-on state, the engagement protrusion 26 engaged with the operation hole 6b of the key 6 is locked and pressed at the tip of the operation hole 6b. 4 is rotated clockwise. As shown in FIG. 9, the key 6 is prevented from escaping upward by the guide 37 until the tip of the key 6 is disengaged from the guide 37, so that the engagement projection 26 is locked by the operation hole 6b. Surely done.
[0039]
Here, the distance between the tip of the key 6 and the tip of the operation hole 6b is set to be large, and the operation projection 6c is protruded from the bottom surface between the key tip and the operation hole tip by press forming. Yes. Thus, by setting the distance from the tip of the key 6 to the tip of the operation hole long, the tip of the operation hole is deviated in the key extraction direction, and the cam projection 4 is rotated by engaging the engagement protrusion 26 accordingly. The timing can be advanced.
[0040]
Further, the function of preventing the escape of the key 6 by the guide 37 is exhibited for a long time to prevent the key 6 from inadvertently escaping upward and slipping out of the cam plate 4 before the cam plate 4 is sufficiently returned and rotated. Can do. Further, by providing the operation projection 6d on the lower surface of the operation surface portion 6c, even when the key tip is detached from the guide 37, the engagement projection 26 is pushed down by the operation projection 6c, and the cam plate 4 is sufficiently returned and rotated. It can be made. As shown in FIG. 9, when the cam plate 4 is rotated to a phase where the key 6 is released from the engaging projection 26, the lock member 31 is released from being pressed by the operation rib 6a, and the lock pin 34 is The lock member 31 is moved upward by the spring 36 at a phase facing the lock groove 35a, and the lock pin 34 is engaged with the lock groove 35a to return to the initial state locked in the switch-off state.
[0041]
Further, if wear occurs due to long-term use or the like, when the key 6 is pulled out, there is a risk that the key plate 6 may slip through without the cam plate 4 sufficiently rotating and returning. In such a case, the key 6 again. 10 and 11, the switch-off operation projection 26 is contacted with the key 6 to rotate the cam plate 4 counterclockwise as shown in FIGS. 10 and 11. As described above, when the cam plate 4 is largely rotated counterclockwise, the restraining cam portion 24 pushes the plunger 3 and the switch-off state is brought about. Further, when the cam plate 4 is rotated largely counterclockwise from the normal position, the lock pin 34 is engaged with the lock groove 35b of the locking recess 35, and the plunger is pushed in by the check cam portion 24. Thereafter, the operation with the key 6 becomes impossible, and the cam plate 24 is not erroneously rotated any more, and the switch-off failure state is maintained.
[0042]
As shown in FIG. 12, even when the key 6 is pulled out obliquely, the lock pin 34 comes into contact with the inner peripheral wall as the stopper portion of the locking recess 35, and the cam plate 4 is moved from the normal switch-off position. Is also prevented from being rotated clockwise.
[0043]
As a result, even if the key is pulled out obliquely, it does not return to the normal switch-off position and rotate too clockwise.
[0044]
(Embodiment 2)
FIGS. 13 to 17 show an example of a mode in which the key 6 is inserted into and removed from the key insertion port 5 provided on the upper surface and the switch switching operation is performed. In this embodiment, the rotation direction of the cam plate 4 is opposite to that in the above-described embodiment, but the operation and function are the same, and therefore the same or equivalent function as in the above-described embodiment. The parts and parts to be provided are denoted by the same reference numerals, and the description thereof is omitted.
[0045]
【The invention's effect】
As described above, according to the present invention, since the lock member is configured not to move in the rotational axis direction of the cam member, the space in the front-rear direction of the switch of the rotation lock mechanism is reduced, and the entire switch can be thinned. It has become possible.
[0048]
Further, if the cam member is erroneously rotated, the switch is turned off and the key operation becomes impossible, so that the safety is excellent.
[0049]
Furthermore, since the range of the return rotation of the cam portion is regulated by the contact between the lock member and the stopper portion, the cam member is not unduly rotated even when the key is inclined, and the reliability is improved. Effective above.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an overall appearance of a key switch according to a first embodiment of the present invention.
FIG. 2 is a longitudinal front view of the entire key switch according to the first embodiment.
FIG. 3 is a front view showing a rotation lock mechanism in the first embodiment.
4 is a longitudinal side view showing a rotation lock mechanism in Embodiment 1. FIG.
5 is an exploded perspective view showing a cam plate and a lock member in Embodiment 1. FIG.
FIG. 6 is a longitudinal front view of a main part showing an initial state in which a key is inserted in the first embodiment.
FIG. 7 is a longitudinal front view of the main part showing a state where the key is inserted and the cam plate is slightly rotated in the first embodiment.
FIG. 8 is a longitudinal front view showing a key insertion completion state in the first embodiment.
FIG. 9 is a longitudinal front view of the main part showing a state close to the end of the key extraction in the first embodiment.
FIG. 10 is a longitudinal front view of the main part showing a state where the cam member is unjustly rotated in the first embodiment.
FIG. 11 is a longitudinal sectional front view of a main part showing a state in which the cam member is unduly rotated in the first embodiment.
FIG. 12 is a longitudinal front view of the main part showing a state in which the key is obliquely extracted in the first embodiment.
FIG. 13 is a longitudinal front view of a main part showing a state in which a key is extracted in a second embodiment according to the present invention.
14 is a longitudinal front view showing a key insertion completion state in the second embodiment. FIG.
FIG. 15 is a longitudinal front view of the main part showing a state close to the end of the key extraction in the second embodiment.
FIG. 16 is a longitudinal front view of the main part showing a state in which the cam member is unjustly rotated in the second embodiment.
FIG. 17 is a longitudinal front view of the main part showing a state in which the key is extracted obliquely in the second embodiment.
FIG. 18A is a plan view of a main part showing an initial state in a conventional example.
(B) It is the side view.
FIG. 19A is a plan view of a main part showing a key insertion completion state in a conventional example.
(B) It is the side view.
[Explanation of symbols]
2 Switch mechanism 3 Plunger 4 Cam member (cam plate)
5 Key insertion port 6 Key 21 Support shaft 22 Cam part 23 Cam part 24 Checking cam part 26 Engaging protrusion 30 Rotation lock mechanism 31 Lock member

Claims (2)

The cam member is rotated according to the insertion / extraction of the key into / from the key insertion port, and the plunger that contacts the outer peripheral cam surface of the cam member is displaced in conjunction with the rotation of the cam member to switch the switch mechanism. And a key switch provided with a rotation lock mechanism for preventing rotation of the cam member in the key extraction state,
A lock member that is displaceable in a direction parallel to a rotation surface perpendicular to the support shaft of the cam member, and a bias member that biases the lock member toward a lock position that engages the cam member. And the lock member is displaceable to the unlock position against the spring by contact with a key,
On the outer peripheral surface of the cam member, a switch-off cam portion acting on the plunger, a switch-on cam portion acting on the plunger, and the cam member acting on the plunger to switch off when the cam member is erroneously rotated. The cam member is formed with a locking groove that engages with the lock member when the cam member is erroneously rotated and restricts the rotation of the cam member. Key switch characterized by Wherein the cam member, the extraction range of rotation of the direction of the key, the key switch according to claim 1, wherein the stopper portion for regulating the contact between the locking member is formed.

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