Latch mechanism

Abstract

To select a taper angle that can relax a manufacturing tolerance of components and does not increase the possibility of a latch being released when an external force is a high load when designing a latch mechanism in which a taper angle is provided on a surface where a latch pin and a latch groove contact with each other.SOLUTION: A latch groove 5 includes: a first tapered surface 11 that is tilted by a first taper angle θ1 toward the opposite side of an insertion direction 40 with respect to a fitting direction 41 of a latch pin 3; and a second tapered surface 12 that is tilted by a second taper angle θ2 toward the opposite side of the insertion direction 40 with respect to the fitting direction 41. A third tapered surface 31 of the latch pin 3 is tilted by the first taper angle θ1 toward the opposite side of the insertion direction 40 with respect to the fitting direction 41, and a fourth tapered surface 32 of the latch pin 3 is tilted by the second taper angle θ2 toward the opposite side of the insertion direction 40 with respect to the fitting direction 41. In a latched state, the third tapered surface 31 is pressed against the first tapered surface 11 by an extension force of a spring 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a latch mechanism. [Background technology]

[0002] A specific example of a conventional latch mechanism is the latch mechanism disclosed in Patent Document 1. In the latch mechanism disclosed in Patent Document 1, connecting members A and B rotate relative to each other via a drive shaft, and when they rotate to the desired angle, a spring mounted on connecting member B causes a pin to engage with a latch groove provided on connecting member A, completing the latching process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-293780 Summary of the Invention [Problem to be solved by the invention]

[0004] The surface where the latch pin and the latch groove come into contact when the latch is complete is inclined with respect to the fitting direction of the latch pin. The inclination of this surface is called the taper angle. The effects of providing a taper angle are as follows:

[0005] (Effect 1) It is possible to relax the manufacturing tolerances of the components. When a taper angle is provided, the latch pin starts to engage with the latch groove at the latch start position, which is before the latch complete position. Therefore, even if there is a manufacturing error in each part, the latch pin engages with the latch groove, and the spring's extension force presses the latch pin against the tapered surface of the latch groove and makes contact, and the latch pin reaches the latch complete position and completes the latch. Here, the tapered surface is a surface that has a taper angle. If no taper angle is provided, the difference between the latch start position and the latch completion position of the latch pin in the insertion direction approaches zero, so in this case, unless the manufacturing tolerances allowed for each part are tightened, the latch pin will not be inserted even when it reaches the latch completion position, or a gap will be created on the surface where the latch pin and the latch groove contact even when the latch pin fits into the latch groove.

[0006] (Effect 2) If the external force is high, the latch may be released. When an external force in the direction to release the latch acts on components A and B in the fully latched state, a component of the external force according to the taper angle acts on the latch pin in the direction opposite to the mating direction. If the extension force of the spring is smaller than this component force, the latch pin will start to move in the direction opposite to the mating direction, and eventually all of the latch pins may come out of the latch groove and the latch will be released. On the other hand, increasing the extension force of the spring increases the friction between the parts during the latching operation, which requires an increased force (motor output torque, etc.) to latch, and as a result, resources such as mass and power must be increased.

[0007] The above two effects are contradictory. Therefore, when designing a latch mechanism in which a taper angle is provided on the surface where the latch pin and latch groove contact, there was a challenge in that it was necessary to select the taper angle by comparing and considering the two contradictory effects. The present disclosure aims to select a taper angle when designing a latch mechanism in which a taper angle is provided on the surface where the latch pin and latch groove contact, without having to compare and consider two conflicting effects: a larger taper angle allows for looser manufacturing tolerances for components, but on the other hand increases the likelihood that the latch will be released when a high external load is applied. [Means for solving the problem]

[0008] The latch mechanism according to the present disclosure comprises: a first member having a latch groove; A second member that moves along an insertion direction inside the first member; A spring provided on the second member; a latch pin that protrudes in the fitting direction inside the first member due to the extension force of the spring; A latch mechanism comprising: The latch pin fits into the latch groove, the latch groove includes a first tapered surface inclined by a first taper angle in a direction opposite to the insertion direction with respect to the fitting direction, and a second tapered surface adjacent to a lower side of the first tapered surface in the fitting direction and inclined by a second taper angle in a direction opposite to the insertion direction with respect to the fitting direction, the first tapered surface and the second tapered surface are surfaces located on opposite sides in the insertion direction, the second taper angle is smaller than the first taper angle; the latch pin includes a third tapered surface and a fourth tapered surface; the third tapered surface is inclined by the first taper angle with respect to the fitting direction toward the opposite side of the insertion direction, the fourth tapered surface is adjacent to and below the third tapered surface in the fitting direction, and is inclined by the second taper angle with respect to the fitting direction in a direction opposite to the insertion direction, In a latched state in which the latch pin is engaged with the latch groove, The third tapered surface is pressed against the first tapered surface by the expansion force of the spring. Effect of the Invention

[0009] According to the present disclosure, the latch groove includes a first tapered surface and a second tapered surface. The latch pin includes a third tapered surface and a fourth tapered surface. Here, the second tapered surface is adjacent to the lower side of the first tapered surface in the mating direction. The first tapered surface is inclined by a first taper angle toward the opposite side of the insertion direction. The second tapered surface is inclined by a second taper angle toward the opposite side of the insertion direction. The third tapered surface is inclined by the first taper angle toward the opposite side of the insertion direction. The fourth tapered surface is inclined by a second taper angle toward the opposite side of the insertion direction. The second taper angle is smaller than the first taper angle. In the latched state, the third tapered surface is pressed against the first tapered surface. Therefore, according to the present disclosure, the first tapered surface, the second tapered surface, the third tapered surface, and the fourth tapered surface are provided with two types of taper angles, so that the manufacturing tolerance of the components can be relaxed, and the latch is not released even when an external force is a high load. Therefore, according to the present disclosure, when designing a latch mechanism in which a taper angle is provided on the surface where the latch pin and latch groove contact, the taper angle can be selected without having to compare two opposing effects. [Brief description of the drawings]

[0010] [Figure 1] 1A and 1B are diagrams showing a configuration example of a latch mechanism 100 according to a first embodiment. [Diagram 2] 1A to 1E are diagrams showing the operation sequence of the latch mechanism 100 of embodiment 1, in which (a) is a diagram showing the state before insertion begins, (b) is a diagram showing insertion in the middle, (c) is a diagram showing the start of the latch operation, (d) is a diagram showing the latch operation, and (e) is a diagram showing the completed latch state. [Diagram 3] 5A and 5B are diagrams illustrating a case where an external force acts on the latch mechanism 100 according to the first embodiment, in which (a) shows a latched state, and (b) shows a state in which an external force acts on the latch mechanism 100. [Figure 4] 1A and 1B are diagrams illustrating a latch mechanism 200 according to a conventional technique, in which (a) shows the start of mating, (b) shows mating in the middle, and (c) shows a state in which latching is completed. [Diagram 5]1A and 1B are diagrams illustrating a latch mechanism 200 according to a conventional technique, in which (a) shows the start of mating, and (b) shows a state in which latching is completed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In the description of the embodiments and the drawings, the same elements and corresponding elements are denoted by the same reference numerals. Descriptions of elements denoted by the same reference numerals will be omitted or simplified as appropriate.

[0012] Embodiment 1 Hereinafter, the present embodiment will be described in detail with reference to the drawings.

[0013] ***Configuration Description*** 1 shows a latch mechanism 100 according to the present embodiment in a fully latched state. The latch mechanism 100 is composed of a member 1, a member 2, a latch pin 3, and a spring 4. The fully latched state is a state in which latching is completed and the latch pin 3 is fitted into the latch groove 5. The manufacturing procedure for the latch mechanism 100 corresponds to a method for manufacturing the latch mechanism.

[0014] The member 1 is provided with a latch groove 5. The member 1 corresponds to a first member. The latch groove 5 includes a contact surface 11 , a contact surface 12 , a contact surface 13 , and a contact surface 14 . The contact surface 11 is a surface of the latch groove 5 that is inclined toward the insertion opening by a taper angle θ1 with respect to the fitting direction 41. The contact surface 11 contacts a first taper surface. The taper angle θ1 corresponds to the first taper angle. The insertion opening side contacts the side opposite to the insertion direction 40. The fitting direction 41 is the direction in which the spring 4 expands and the direction in which the latch pin 3 fits. The opposite direction to the fitting direction 41 is the direction in which the spring 4 contracts. The insertion opening is a portion where the component 2 is inserted into the component 1 . The contact surface 12 is a surface of the latch groove 5 that is located below the contact surface 11 in the fitting direction 41, is adjacent to the lower side of the contact surface 11 in the fitting direction 41, and is a surface that is inclined toward the insertion opening side by a taper angle θ2 with respect to the fitting direction 41. The contact surface 12 abuts on a second taper surface. The taper angle θ2 corresponds to the second taper angle. The contact surface 11 and the contact surface 12 are surfaces that are located on opposite sides in the insertion direction 40. The taper angle θ2 is smaller than the taper angle θ1. The taper angle θ2 may be 0 degrees. When the taper angle θ2 is 0 degrees, the contact surface 12 has a tangent parallel to the fitting direction 41. The contact surface 13 is a surface located on the insertion direction 40 side among the inner surfaces of the component 1 . An insertion direction 40 is a direction in which the member 2 is inserted into the member 1, and is a leftward direction in FIG. The contact surface 14 is a surface located on the upper side in the fitting direction 41 among the inner surfaces of the member 1, and is a surface located on the opposite side to the fitting direction 41.

[0015] The member 2 includes a contact surface 23 and a contact surface 24. The member 2 is provided with a spring 4. The member 2 corresponds to the second member. The second member moves along an insertion direction 40 inside the first member. The contact surface 23 is a surface of the member 2 that is located on the insertion direction 40 side in the latched state. The contact surface 24 is a surface of the member 2 that is located on the opposite side to the fitting direction 41 in the fully latched state.

[0016] The latch pin 3 includes a contact surface 31 and a contact surface 32. The latch pin 3 protrudes in a fitting direction 41 inside the first member due to the extension force of the spring 4. In the fully latched state, the contact surface 31 is inclined toward the insertion opening side by a taper angle θ1 with respect to the fitting direction 41. In the fully latched state, the contact surface 31 is pressed against the contact surface 11 by the extension force of the spring 4. The contact surface 31 abuts against the third taper surface. The contact surface 32 is a surface located below the contact surface 31 in the mating direction 41 in the latched state, adjacent to the contact surface 31 below in the mating direction 41, and inclined by a taper angle θ2 toward the insertion opening side with respect to the mating direction 41. The contact surface 32 abuts against the fourth tapered surface. The contact surfaces 31 and 32 are adjacent to each other. The contact surfaces 31 and 32 are stored inside the member 2 immediately before the start of latching. The latch pin 3 slides along the contact surface 11 due to the extension force of the spring 4 while the member 2 is moving inside the member 1 along the insertion direction 40 . In the latched state, the contact surface 31 of the latch pin 3 comes into contact with the latch groove 5 due to the extension force of the spring 4. In the latched state, the contact surfaces 31 and 32 protrude from the member 2 in the fitting direction 41 due to the extension force of the spring 4. Here, in the latched state, i.e., when the contact surface 11 and the contact surface 31 are in contact with each other, a gap exists between the contact surface 12 and the contact surface 32. When the latch pin 3 is pressed against the contact surface 11 by the extension force of the spring 4, a component force is generated that presses the member 2 in the insertion direction 40, so that the contact surface 23 is pressed against the contact surface 13 and the contact surface 24 is pressed against the contact surface 14. When the three contact surfaces, contact surface 31, contact surface 23, and contact surface 24, are pressed against the respective surfaces inside member 1 in the latched state, there are no gaps at each contact site inside latch mechanism 100. Specifically, there is no gap between contact surface 11 and contact surface 31, there is no gap between contact surface 13 and contact surface 23, and there is no gap between contact surface 14 and contact surface 24. Therefore, member 1 and member 2 are joined with high rigidity. Each contact site is a site inside member 1 that is in contact with a component other than member 1. The gaps at each contact site correspond to clearance or backlash. The contact forces pressing each of contact surfaces 31, 23, and 24 against the respective internal surfaces of member 1 are proportional to the extension force of spring 4. If an external force that reduces each contact force is input and the input external force exceeds each contact force, gaps will be generated at each contact site, and the rigidity of the connection between member 1 and member 2 will decrease.

[0017] 2 shows a specific example of an operation sequence of the latch mechanism 100. The operation sequence of the latch mechanism 100 will be described with reference to FIG.

[0018] First, as shown in (a) of Fig. 2, the member 2 is inserted into the member 1 along the insertion direction 40. In (a) of Fig. 2, the member 2 is inserted from the right side to the left side. Thereafter, the member 2 continues to be inserted into the member 1 along the insertion direction 40.

[0019] 2(b), the latch pin 3 is pushed upward in the fitting direction 41 along a slope provided inside the member 1. At this time, the spring 4 contracts upward in the fitting direction 41. As a result, the latch pin 3 is pushed into the member 2.

[0020] 2(c), when the edge of the contact surface 32 (the lower end of the contact surface 32 in the fitting direction 41) and the edge of the contact surface 11 (the upper end of the contact surface 11 in the fitting direction 41) coincide with each other, the fitting of the latch pin 3 begins. At this time, a gap 17 exists between the member 1 and the member 2.

[0021] Next, as shown in FIG. 2( d ), the latch pin 3 protrudes downward in the fitting direction 41 from the member 2 , and the lower end of the latch pin 3 in the fitting direction 41 slides along the contact surface 11 .

[0022] Next, the latching is completed as shown in (e) of Fig. 2. Note that (e) of Fig. 2 is the same as Fig. 1, and shows the latching completed state.

[0023] 2 shows a specific example in which the members 1 and 2 execute a relative translational motion. It goes without saying that the same latched state as in this example can be obtained even if the members 1 and 2 execute a relative rotational motion in which they move in the tangent direction of a circle. In this case, the insertion direction 40 may be a direction along a part of a circle.

[0024] FIG. 3 is a diagram illustrating a case where an external force acts on the latch mechanism 100 in a direction to release the latch.

[0025] 3(a) is the same as FIG. 1 and shows the latched state. At this time, the contact surface 11 and the contact surface 31 are in contact with the contact surface 13 and the contact surface 23 due to the extension force of the spring 4. However, a gap exists between the contact surface 12 and the contact surface 32.

[0026] 3(b) shows a case where an external force 50 is applied to the member 2. The external force 50 is a force that attempts to pull out the member 2 in the opposite direction to the insertion direction 40. In this case, the contact force at the contact surface 11 increases due to the external force 50, and a component force according to the taper angle θ1 is generated, generating a push-up force 51. The push-up force 51 is a force that pushes the latch pin 3 upward in the fitting direction 41. When the pushing force 51 exceeds the extension force of the spring 4, the latch pin 3 moves upward in the fitting direction 41, and the member 2 moves in the opposite direction to the insertion direction 40. As a result, a gap 16 is generated between the contact surface 13 and the contact surface 23. Furthermore, when the member 2 moves in the opposite direction to the insertion direction 40, the contact surface 12 and the contact surface 32 come into contact with each other. Here, the taper angle θ2 of the contact surface 12 is smaller than the taper angle θ1 of the contact surface 11. Therefore, the pushing-up force 51 decreases due to the contact between the contact surface 12 and the contact surface 32. Note that if the pushing-up force 51 does not exceed the extension force of the spring 4, the latch pin 3 will not be pushed upward in the fitting direction 41. At this time, a gap is generated between the contact surface 11 and the contact surface 31. When the external force 50 no longer acts on the member 2, the upward pushing force 51 disappears, the latch pin 3 moves downward in the mating direction 41 again, and the contact surface 11 and the contact surface 31 come into contact with each other, thereby returning the latch mechanism 100 to the state shown in (a) of Figure 3.

[0027] FIG. 4 illustrates a prior art latch mechanism 200 and its operating sequence. In the latch mechanism 200, the latch pin 6 and the latch groove 8 are each provided with only one type of taper angle, which is a taper angle θ1.

[0028] 4(a) shows the moment when the latch pin 6 starts to fit into the latch groove 8 (the latch pin 6 starts to move downward in the fitting direction 41). At this time, a gap 18 exists between the member 1 and the member 2.

[0029] FIG. 4(b) shows a state during the latching operation, in which the latch pin 6 moves downward in the fitting direction 41 along the contact surface 11 as the member 2 moves along the insertion direction 40.

[0030] 4(c) shows the latched state. Due to the extension force of the spring 4 and its component force, the members 1 and 2 are in contact with each other at the contact surface 13, and the latch pin 6 and latch groove 8 are in contact with each other at the contact surface 11. As shown in Fig. 4(c), when an external force 50 acts on the member 2, a component force 52 is generated by the contact surface 11. When the component force 52 exceeds the extension force of the spring 4, the latch pin 6 is pushed upward in the fitting direction 41, and the member 2 moves in the opposite direction to the insertion direction 40. When the external force 50 continues to act, the component force 52 is generated continuously, and the latch pin 6 is further pushed upward in the fitting direction 41 while the member 2 further moves in the opposite direction to the insertion direction 40. Thereafter, the latch mechanism 200 passes through the state shown in Fig. 4(b) and the state shown in Fig. 4(a) in sequence, and the latch in the latch mechanism 200 is released.

[0031] There are two countermeasures to prevent such an unlatching event: Countermeasure 1: Make the extension force of the spring 4 sufficiently greater than the component force 52 generated by the external force 50. Countermeasure 2: Reduce the component force 52 by reducing the taper angle θ1.

[0032] When Countermeasure 1 is implemented, the latch pin 6 and member 1 are pressed against each other by a large extension force from the start of latching to the completion of latching. Furthermore, due to the reaction force, member 2 comes into contact with member 1 at the contact surface 24. At this time, in order to move member 2 along the insertion direction 40, it is necessary to continue to press member 2 along the insertion direction 40 by applying a force to member 2 that counters the frictional force generated at the contact surface 24. Therefore, as a specific example, it becomes necessary to increase the output of an actuator or the like. Furthermore, in order to increase the extension force of spring 4, a mass is required to reinforce spring 4. Here, resources (power and mass) are extremely limited, especially in a latch mechanism for space use, so the output and mass related to Measure 1 become a major problem.

[0033] Each of the advantages and disadvantages of the latch mechanism 200 are described below. (Advantages) When latching begins, a gap 18 exists, and the latch pin 6 advances downward in the fitting direction 41 until the latching is completed when the member 2 comes into contact with the contact surface 13. Therefore, even if the dimensional accuracy of the components of the latch mechanism 200 is somewhat low, the low dimensional accuracy can be absorbed by the amount of fitting of the latch pin 3 changing slightly. Also, when latching is completed, all gaps disappear at the contact surface 11 due to the extension force of the spring 4. Therefore, the connection rigidity between the members 1 and 2 is high.

[0034] (Disadvantages) When an external force 50 exceeding the extension force of the spring 4 is applied to the member 2, the latch is released.

[0035] FIG. 5 shows a case where Countermeasure 2 is implemented for the latch mechanism 200 shown in FIG. 4, that is, the taper angle is set to θ2 which is smaller than θ1.

[0036] 5(a) shows the moment when the latch pin 7 starts to fit into the latch groove 9 (the latch pin 7 starts to move downward in the fitting direction 41). At this time, a gap 19 exists between the member 1 and the member 2. Here, the gap 19 is smaller than the gap 18 corresponding to the taper angle θ1.

[0037] FIG. 5(b) shows the fully latched state, in which the latch pin 7 is latched into the latch groove 9.

[0038] Each of the advantages and disadvantages of the latch mechanism 200 shown in FIG. 5 are described below. (Advantages) When an external force 50 acts on the member 2, the latch pin 7 comes into contact with the contact surface 12. However, in this case, almost no component force is generated that pushes the latch pin 7 upward in the fitting direction 41. Therefore, the latch is not released.

[0039] (Disadvantages) When the distance between contact surface 23 and contact surface 32 is greater than the distance between contact surface 13 and contact surface 12, the latch pin 7 cannot fit into the latch groove 9, making latching impossible. Also, when the distance between contact surface 12 and contact surface 13 is smaller than the distance between contact surface 23 and contact surface 32, in the fully latched state, the extension force of spring 4 does not act on contact surface 13 and contact surface 12, so that gaps exist near each of contact surface 13 and contact surface 12. Therefore, the coupling rigidity between member 1 and member 2 in the fully latched state is lower than that of latch mechanism 200 shown in FIG. 4.

[0040] The latch mechanism 100 overcomes the disadvantages of both the latch mechanism 200 with a taper angle of θ1 and the latch mechanism 200 with a taper angle of θ2. The latch mechanism 100 also has the advantages of both. That is, in the latched state, the latch mechanism 100 is in the following state. The taper angle is θ1 at the entrance of the latch groove 5. Therefore, a gap 17 exists when the latch starts. Therefore, even if the dimensional accuracy of the components is somewhat low, the low dimensional accuracy can be absorbed by the slight change in the amount of engagement of the latch pin 3. In the latched state, when no external force 50 acts on the member 2, the extension force of the spring 4 causes the latch pin 3 and the latch groove 5 to contact each other at the contact surface 11 having a taper angle θ1, thereby eliminating all gaps in the latch mechanism 100. Therefore, the connection rigidity between the member 1 and the member 2 is relatively high. When an external force 50 acts on the member 2 in the fully latched state, the member 1 and the member 2 come into contact with each other at the contact surface 12 having a taper angle of θ2, so that the component force 52 pushing up the latch pin 3 becomes smaller. Therefore, the latch is not released.

[0041] ***Explanation of the Effects of the First Embodiment*** In existing technology, the contact surface between the latch pin and the latch groove in the fully latched state is usually provided with a taper angle, like a wedge. By providing a taper angle, a component force is generated in the direction in which the spring presses parts A and B together in the fully latched state. As a result, parts A and B are pressed together with a stronger force, which increases the rigidity when connected. On the other hand, if a taper angle is provided, when an external force to release the latch acts on component B in the fully latched state, a component of the external force acts in the opposite direction to the mating direction due to the contact surface between the latch pin and the latch groove. If this component force becomes greater than the pressing force of the spring, the latch pin is pushed out and the latch is released.

[0042] In addition, regarding the size of the taper angle, when the taper angle is large, the component of the force of the spring pressing members A and B together in the fully latched state is small. However, in this case, the distance between the position of the latch pin in the insertion direction when the latch starts and the position of the latch pin in the insertion direction when the latch is fully latched can be increased. This increases the robustness against dimensional tolerances of the components. On the other hand, when the taper angle is small, the component of the force of the spring pressing members A and B together in the latched state becomes large. However, in this case, the distance between the position of the latch pin in the insertion direction when latching begins and the position of the latch pin in the insertion direction when latching is complete becomes small. Therefore, unless the components are manufactured with high precision, gaps may occur between the components in the latched state, or the latch pin may not be able to fit into the latch groove. For this reason, in the prior art, a trade-off between the following trade-offs is required when selecting the magnitude of the taper angle:

[0043] Increasing the taper angle in order to increase the distance between the position of the latch pin in the insertion direction when latching begins and the position of the latch pin in the insertion direction when latching is complete (relaxing the manufacturing tolerances of the parts). The taper angle is made small so that the latch will not be released even when a large external force is applied.

[0044] In this embodiment, two types of taper angles are provided for each of the latch pin 3 and the latch groove 5. Specifically, by making the taper angle at the entrance of the latch groove 5 relatively large, the distance between the position of the latch pin in the insertion direction at the start of latching and the position of the latch pin in the insertion direction at the completion of latching is secured. Also, the taper angle near the bottom of the latch groove 5 is made relatively small. This makes it possible to realize a latch mechanism 100 in which the latch is not released even when a large external force is applied. Therefore, the latch mechanism 100 according to the present embodiment is a latch mechanism 100 that addresses the above-mentioned trade-offs.

[0045] Furthermore, when the taper angle θ2 is 0 degrees, even if the friction coefficient of the contact surface 12 is zero, no component force is generated that pushes the latch pin 3 upward in the fitting direction 41. Therefore, in this case, the latch will not be released even if a large external force is applied in the direction to release the latch.

[0046] ***Other embodiments*** Although the first embodiment has been described, it is possible to combine a plurality of parts of the present embodiment. Alternatively, it is possible to partially implement the present embodiment. In addition, the present embodiment may be modified in various ways as necessary, and may be implemented in any combination, either as a whole or in part. The above-described embodiment is essentially a preferred example, and is not intended to limit the scope of the present disclosure, its applications, and uses. The described procedure may be modified as appropriate.

[0047] Various aspects of the present disclosure are summarized below as appendices.

[0048] (Appendix 1) a first member having a latch groove; A second member that moves along an insertion direction inside the first member; A spring provided on the second member; a latch pin that protrudes in the fitting direction inside the first member due to the extension force of the spring; A latch mechanism comprising: The latch pin fits into the latch groove, the latch groove includes a first tapered surface inclined by a first taper angle in a direction opposite to the insertion direction with respect to the fitting direction, and a second tapered surface adjacent to a lower side of the first tapered surface in the fitting direction and inclined by a second taper angle in a direction opposite to the insertion direction with respect to the fitting direction, the first tapered surface and the second tapered surface are surfaces located on opposite sides in the insertion direction, the second taper angle is smaller than the first taper angle; the latch pin includes a third tapered surface and a fourth tapered surface; the third tapered surface is inclined by the first taper angle with respect to the fitting direction toward the opposite side of the insertion direction, the fourth tapered surface is adjacent to and below the third tapered surface in the fitting direction, and is inclined by the second taper angle with respect to the fitting direction in a direction opposite to the insertion direction, In a latched state in which the latch pin is engaged with the latch groove, A latch mechanism in which the third tapered surface is pressed against the first tapered surface by the extension force of the spring.

[0049] (Appendix 2) 2. The latch mechanism of claim 1, wherein while the second member moves inside the first member along the insertion direction, the latch pin slides along the first tapered surface due to the extension force of the spring.

[0050] (Appendix 3) In the latched state, There is no gap between the first tapered surface and the third tapered surface, 3. The latch mechanism according to claim 1, wherein a gap exists between the second tapered surface and the fourth tapered surface.

[0051] (Appendix 4) 4. The latch mechanism according to claim 1, wherein in the latched state, a component force of the extension force of the spring presses a surface of the second member located on the insertion direction side against a surface of the first member located on the insertion direction side.

[0052] (Appendix 5) 5. The latch mechanism according to claim 1, wherein in the latched state, a component force of the extension force of the spring presses a surface of the second member located on the opposite side of the mating direction against a surface of the first member located on the opposite side of the mating direction.

[0053] (Appendix 6) 6. The latch mechanism of claim 1, wherein the second taper angle is 0 degrees. [Explanation of symbols]

[0054] 1,2 Members, 3,6,7 Latch pin, 4 Spring, 5,8,9 Latch groove, 11,12,13,14,23,24,31,32 Contact surface, 16,17,18,19 Gap, 40 Insertion direction, 41 Fitting direction, 50 External force, 51 Push-up force, 52 Force component, 100,200 Latch mechanism.

Claims

1. a first member having a latch groove; A second member that moves along an insertion direction inside the first member; A spring provided on the second member; a latch pin that protrudes in the fitting direction inside the first member due to the extension force of the spring; A latch mechanism comprising: The latch pin fits into the latch groove, the latch groove includes a first tapered surface inclined by a first taper angle in a direction opposite to the insertion direction with respect to the fitting direction, and a second tapered surface adjacent to a lower side of the first tapered surface in the fitting direction and inclined by a second taper angle in a direction opposite to the insertion direction with respect to the fitting direction, the first tapered surface and the second tapered surface are surfaces located on opposite sides in the insertion direction, the second taper angle is less than the first taper angle; the latch pin includes a third tapered surface and a fourth tapered surface; the third tapered surface is inclined by the first taper angle with respect to the fitting direction toward the opposite side of the insertion direction, the fourth tapered surface is adjacent to a lower side of the third tapered surface in the fitting direction and is inclined by the second taper angle with respect to the fitting direction in a direction opposite to the insertion direction, In a latched state in which the latch pin is engaged with the latch groove, A latch mechanism in which the third tapered surface is pressed against the first tapered surface by the extension force of the spring.

2. 2. The latch mechanism according to claim 1, wherein the latch pin slides along the first tapered surface due to the extension force of the spring while the second member moves inside the first member along the insertion direction.

3. In the latched state, There is no gap between the first tapered surface and the third tapered surface, 3. The latch mechanism according to claim 1, wherein a gap exists between the second tapered surface and the fourth tapered surface.

4. 3. The latch mechanism according to claim 1, wherein in the latched state, a component force of the extension force of the spring presses the surface of the second member located on the insertion direction side against a surface of the interior of the first member located on the insertion direction side.

5. 3. The latch mechanism according to claim 1, wherein in the latched state, a component force of the extension force of the spring presses a surface of the second member located on the opposite side of the mating direction against a surface of the interior of the first member located on the opposite side of the mating direction.

6. 3. The latch mechanism according to claim 1, wherein the second taper angle is 0 degrees.

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