JP2920020B2 - Cylinder lock 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 cylinder lock which locks a piston rod in an air cylinder or the like at a predetermined retracted position and prevents the piston rod from being retracted from the cylinder by a force acting in the axial direction. It concerns the mechanism.

[0002]

2. Description of the Related Art As a cylinder locking mechanism of this type, for example, a mechanism applied to an air cylinder as shown in FIG. 4 has been considered.

[0003] In this air cylinder, a large-diameter piston chamber 2 is formed in a cylinder main body 1, and partition walls 1 a and 1 b are provided at both ends of the cylinder main body 1. The partition 1 a has a rod insertion hole 3 and a port 4 communicating with the piston chamber 2.

In the partition 1b, there are formed a small-diameter air chamber 5 communicating with the piston chamber 2, a small piston chamber 6 and a port 7 which open vertically in the center of the air chamber 5, and an air chamber. A bypass passage 8 that connects the piston 5 to the piston chamber 2 is formed.

The small piston chamber 6 is provided with a small piston 9a integral with the lock pin 9, and the lock pin 9 is constantly biased toward the air chamber 5 by a spring 10.

[0006] A piston 11 is slidably disposed in the piston chamber 2, and a portion near the inner end of a piston rod 12 penetrating through the rod insertion hole 3 is fixed to the piston 11. The inner end 12a of the piston rod 12 is formed with a tapered guide portion 12b and an annular locking groove 12c.

In such a configuration, by applying air pressure to one of both sides of the piston 11 from the port 4 or 7, the piston 11 is moved forward and backward in the longitudinal direction, and the piston rod 12 is moved out of the cylinder body 1. Let me do.

When the pressure in the small piston chamber 6 decreases while the piston rod 12 is immersed in the cylinder body 1, the lock pin 9 is protruded into the small piston chamber 6 by the spring force of the spring 10. Lock groove 12c
To prevent the piston rod 12 from moving in the axial direction.

In such a configuration, when pressure air is supplied from the port 7 into the small piston chamber 6, the pressure air acts on the small piston 9a and separates from the air chamber 5 against the spring force of the spring 10. Displaced in the direction.

At this time, the lock pin 9 is withdrawn from the air chamber 5, and the lock pin 9 comes off from the locking groove 12c. On the other hand, the bypass passage 8 blocked by the small piston 9a is opened, and the air pressure acts on the piston 11 to move the piston 11 in a direction in which the piston rod 12 projects.

[0011]

However, when air pressure acts on the small piston 9a, the piston rod 1
Air pressure also acts on the second locking groove 12c and the inner end of the piston rod 12, that is, the tapered guide portion 12b, so that the piston rod 12 is displaced.

For this reason, when the piston rod 12 is moved and displaced, the lock pin 9 may come into contact with the side surface of the lock groove 12c before the lock pin 9 comes off the lock groove 12c. In this case, a bending load is applied to the lock pin 9, causing wear and bending of the lock pin 9, which is not preferable for smooth operation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lock mechanism for a cylinder in which the lock pin is not worn or bent by such a bending load.

[0014]

In order to achieve this object, the present invention is to supply a pressure fluid to one of two main fluid chambers defined by a piston in a cylinder body and discharge the fluid from the other. Thus, a piston rod provided integrally with the piston and protruding from one end of the cylinder main body is provided so as to be able to protrude and retract from the cylinder main body, and a pin engaging part of the piston rod which is always located in the one main fluid chamber is provided. A lock portion provided on the cylinder body, wherein a lock pin that projects into the one main fluid chamber and is locked to the pin locking portion when the piston is located at a predetermined position is provided on the cylinder body; A small cylinder portion is provided on the side of the cylinder body perpendicular to the axis, and a small piston integrated with the lock pin is attached to the small cylinder. A small fluid chamber formed between the small piston and the cylinder body, a port communicating with the small fluid chamber is formed in the cylinder body, and supplied to the small fluid chamber from outside. A free valve body that is pressed against the port side in the small fluid chamber by the pressure fluid to be closed and closes the port is mounted on the lock pin so as to be movable in the longitudinal direction, and the lock pin is moved from the one main fluid chamber. A valve locking portion that locks the free valve body and separates the free valve body from the port when the valve is retracted is a cylinder locking mechanism provided on the lock pin.

[0015]

According to such a configuration, when a pressure fluid is supplied from the outside to the small fluid chamber in a state where the lock pin projects into one main fluid chamber in the cylinder body and is engaged with the pin locking portion. The pressure fluid acts on the free valve body, and the free valve body closes the port.

On the other hand, pressure fluid acts on the small piston to displace the small piston in a direction away from the cylinder body. At this time, the lock pin is displaced in a direction to withdraw from the main fluid chamber in the cylinder body. When the lock pin is withdrawn from the one main fluid chamber along with this, the valve locking portion of the lock pin locks the free valve body and separates from the port, and the small fluid chamber and the main fluid chamber. Communication.

By this communication, the pressurized fluid is supplied into the main fluid chamber, and a pressing and moving force acts on the piston in the axial direction.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

In FIG. 3, reference numeral 20 denotes a support member, which has a support plate 21 and a support block 22 fixed to each other. Insertion holes 23 and 24 are formed coaxially in the support plate 21 and the support block 22, and an air guide passage 25 communicating with the insertion hole 24 is formed in the support block 22. An air hose (not shown) is provided in the air guide passage 25.
Is connected to the elbow 26.

The cylinder members 40, 40 'arranged in parallel are attached to the support member 20. Since the cylinder bodies 40 and 40 'and the components mounted inside are the same, the cylinder body 40 will be described,
The description of the cylinder body 40 'is omitted.

The cylinder body 40 has an end tube 41 fitted in the insertion hole 23, an intermediate cylinder 42 fitted in the insertion hole 24, and cylinders 41, 42 fitted in the insertion hole 24. It has a cylinder 43 sandwiched therebetween. An annular groove 44 communicating with the air guide passage 25 is formed on the peripheral surface of the cylindrical body 43 as shown in FIG.

The cylinder body 40 has a cylinder 45 having one end fitted to the outer periphery of the intermediate cylinder 42 and a lid 46 fitted to the other end of the cylinder 45. The cover 46 has a rod hole 47 opening into the cylinder 45 and the rod hole 4.
A port 48 communicating with the port 7 is formed, and a seal ring 49 is attached to an open end of the rod hole 47.

In the cylinder body 40, cylindrical bodies 41, 4
One end side of a piston rod 50 penetrating through 2, 43 is inserted. A small-diameter shaft portion 50b is connected to one end of the piston rod 50 via a step portion 50a.
An external thread 50c is formed at the free end of Ob. A bracket 28 for attaching a jig is fixed to the outer ends of the piston rods 50, 50 with screws 28a (not shown).

An engaging cylinder 5 is provided on the outer periphery of the small diameter shaft portion 50b.
Components such as a collar 52, a piston 53, and a collar 54 are fitted in this order, and these components are sandwiched between a nut 55 screwed to the male screw portion 50c and the step portion 50a. An annular locking groove 51 extending in the circumferential direction is provided on the outer circumference of the locking cylinder 51.
a is formed as a pin locking portion, and
A tapered guide portion 51b is formed on the side a. The piston 53 is slidably fitted in the cylinder 45 to partition the inside of the cylinder body 40 into first and second main fluid chambers A and B. In the figure, S is a seal ring, and J is a bearing.

A stepped mounting hole 56 that opens into the main fluid chamber A is formed in the intermediate cylinder 42 perpendicular to the axis of the cylinder body 40. The mounting hole 56 has a large diameter hole 56a and a small diameter hole 56b. A small cylinder 57 (small cylinder portion) is fitted and fixed in the large-diameter hole portion 56a.
A cylindrical bearing 58 is fitted to 6b.

A small piston 59 having a small-diameter cylindrical portion 59a is slidably fitted in the cylinder body 57a of the small cylinder 57 as shown in FIG. A small fluid chamber C is formed. In the cylindrical bearing 58, a port 58a for communicating the fluid chambers A and C is formed, and a valve seat 58b facing the small fluid chamber C is formed. The small piston 59 is biased by a spring 60 toward the intermediate cylinder 42.

Reference numeral 61 denotes a large-diameter shaft portion 61a and a medium-diameter shaft portion 61.
b, a lock pin having a small diameter shaft portion 61c in this order. A hemispherical guide projection 61e is formed at the center of the end face 61d of the large-diameter shaft portion 61a, a male screw portion 61f is formed at the small-diameter shaft portion 61c, and the large-diameter shaft portion 61a and the medium-diameter shaft portion 6 are formed.
A step 61g is formed as a valve locking portion between the valve 1b.

The large diameter shaft portion 61a of the lock pin 61 is fitted in a cylindrical bearing 58, and the male screw portion 61f is screwed into the small diameter cylindrical portion 59a of the small piston 59. A ring-shaped free valve body 62 whose outer diameter is sufficiently smaller than the inner diameter of the cylinder body 57a is fitted and held on the outer periphery of the middle diameter shaft portion 61b so as to be movable in the longitudinal direction. 62a is a seal rubber of the free valve body 62.

The annular groove 44 and the small fluid chamber C communicate with each other via an air guide passage 63 formed across the support block 22 and the intermediate cylinder 42. In addition, cylinder 4
Ports 48 provided on the lids 46, 46 of 0, 40 ',
The other (not shown) communicates via a connection pipe 31, and the second fluid chambers B of the cylinders 40 and 40 ′ (the other not shown) communicate via a connection pipe 32.

Next, the operation of the air cylinder having such a configuration will be described.

According to such a configuration, the lock pin 61 is projected in the one main fluid chamber A of the cylinder body 40 and is engaged with the locking groove 51a which is a pin locking portion. An air guide hose (not shown), an air guide passage 25, an annular groove 44,
When compressed air, which is a pressurized fluid, is supplied to the small fluid chamber C through the air guide passage 63 and the like, the compressed air is supplied to the free valve body 6.
2, the free valve body 62 closes the port 58a.

On the other hand, a pressure fluid acts on the small piston 59 to displace the small piston 59 in a direction away from the cylinder body 40. At this time, the lock pin 61 is displaced in a direction to withdraw from the main fluid chamber A in the cylinder body 40. Accordingly, as shown in FIG.
When the outer end of a is protruded from the initial position E1 by the distance L1 and reaches the position E2, the lock pin 61 is retracted from the one main fluid chamber A, and the step as the valve locking portion of the lock pin 61 is performed. The portion 61g locks the free valve body 62.

Further, compressed air is supplied to the small fluid chamber,
When the small piston 59 is displaced in a direction away from the cylinder body 40, the outer end of the small-diameter cylindrical portion 59a is displaced from the position E2 by L2 (distance L3 from the initial position E1) as shown in FIG. Reach At this time, the step 61
The free valve body 62 locked to g is separated from the valve seat 58b, opens the port 58a, and connects the small fluid chamber C and the main fluid chamber A. By this communication, the pressurized fluid is supplied into the main fluid chamber A, and a pressing movement force (thrust) in the axial direction acts on the piston 53.

[0034]

As described above, according to the present invention, the small piston is provided on the side of the cylinder body perpendicularly to the axis, and the small piston integrated with the lock pin is disposed in the small cylinder. And a small fluid chamber formed between the cylinder body and a port communicating with the small fluid chamber is formed in the cylinder body, and the small fluid chamber is formed in the small fluid chamber by a pressure fluid supplied from outside. A free valve body that is pressed against the port side and closes the port is mounted on the lock pin so as to be movable in the longitudinal direction, and the free valve body is engaged when the lock pin is withdrawn from the one main fluid chamber. Since the lock pin is provided with a valve locking portion for stopping and separating from the port, the lock pin is withdrawn from the main fluid chamber by fluid pressure, and the lock pin from the locking portion is removed. When to disengage the the thrust of the piston rod in the axial direction can be prevented from acting.

As a result, it is possible to reliably prevent a bending load from acting on the lock pin from the piston rod, and to prevent the lock pin from being worn or bent due to the bending load.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a main part showing an embodiment of a cylinder lock mechanism according to the present invention.

FIGS. 2 (a) and 2 (b) are explanatory views of the operation state of the lock mechanism shown in FIG.

FIG. 3 is an overall explanatory view showing an air cylinder having the structure of FIGS. 1 and 2 in a partially sectioned manner.

FIG. 4 is an explanatory view showing a prior art of an air cylinder.

[Explanation of symbols]

A, B: main fluid chamber C: small fluid chamber 40: cylinder body 53: piston 51a: locking groove (pin locking part) 57: small cylinder (small cylinder part) ) 58a ... port 59 ... small piston 50 ... piston rod 62 ... free valve body 61 g ... stepped portion (Bengakaritome portion)

Continuation of the front page (56) References JP-A 63-53908 (JP, U) JP-B 48-41191 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) F15B 15 / 00-15/28

Claims (1)

(57) [Claims] 1. One end of the cylinder body provided integrally with the piston by supplying a pressure fluid to one of two main fluid chambers defined by a piston in the cylinder body and discharging the fluid from the other. A piston rod protruded from the cylinder body is provided so as to be able to protrude and retract from the cylinder main body, and a pin locking portion is provided on a part of the piston rod which is always located in the one main fluid chamber, and when the piston is located at a predetermined position. A lock mechanism for a cylinder in which a lock pin protruding into the one main fluid chamber and locked to the pin locking portion is mounted on the cylinder body, wherein a small cylinder portion is provided on a side portion of the cylinder body perpendicularly to an axis. A small piston integrated with the lock pin is disposed in the small cylinder portion, and the small piston and the cylinder A small fluid chamber is formed between the body and the body, a port communicating with the small fluid chamber is formed in the cylinder body, and a pressure fluid supplied from the outside to the small fluid chamber is provided in the small fluid chamber to the port side. A free valve body that is pressed against and closes the port is mounted on the lock pin so as to be movable in the longitudinal direction, and locks the free valve body when the lock pin is withdrawn from the one main fluid chamber. A lock mechanism for a cylinder, wherein a valve locking portion for separating from the port is provided on the lock pin.