JPS6212496Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feed rate control device for controlling the speed of a moving load such as a manually or pneumatically operated machine tool to a constant rate.

The device shown in U.S. Pat.
and the diaphragm 4 are fixed with a collar, and the piston rod 1 and the diaphragm 4 are fixed by being wrapped with a thread. This method takes time to assemble and the fixing method requires skill.Furthermore, since the spring that biases the diaphragm guide to restore the piston rod is strong, the piston rod can be restored by itself. If this type of device is used to repeatedly stop work at a single work end position, the piston rod will return to its original state when the load is removed, that is, when one work is completed, as described above. Not suitable for work.

Unlike the installation in the above-mentioned US patent, it has been proposed that a bead is provided on the lower end surface of the diaphragm and the diaphragm is sandwiched between the outer cylindrical portions (Japanese Utility Model Publication No. 55-48217). A diaphragm with this shape is easy to install, but
There is a problem in that the mounting structure as a whole becomes larger.

The purpose of the present invention is to have a diaphragm mounting structure that is easy to assemble, provides a perfect seal, and ensures smooth rolling action of the diaphragm.
Can stand still at any position when the load is removed,
It is an object of the present invention to provide a feed rate control device which can be made compact as a whole and is restored by injecting compressed air.

In order to achieve the above object, the feed rate control device according to the present invention is a piston-cylinder type brake device in which a space in which brake fluid flows and an air space in a cylinder housing are separated by a flexible substantially cylindrical diaphragm. , the diaphragm has a thin-film cylindrical large-diameter diaphragm portion corresponding to the inner diameter of the housing, and a thin-film cylindrical small-diameter diaphragm portion corresponding to the outer diameter of a piston rod connected to the cylindrical portion via a thick rib. , an annular bead thicker than the wall thickness of the diaphragm is provided at the end of each diaphragm portion, and the beads of the large diameter diaphragm portion and the small diameter diaphragm portion are each airtightly fixed to the cylinder housing and the piston rod with mounting collars. , a diaphragm guide is provided in the air space, the diaphragm guide being pressed against the diaphragm in the axial direction by a spring sufficient to stop the piston rod at that position when the external force applied to the piston rod is removed, thereby forming the air space. An opening is provided in the cylinder housing to allow compressed air to be introduced to return the piston rod.

According to the above configuration, the purpose of the present invention can be completely achieved.

The configuration of the present invention will be explained in more detail below with reference to the drawings and the like.

FIG. 2 is a structural diagram showing an embodiment of the present invention, with the left side showing the normal state and the right side showing the piston rod pushed in to the maximum extent.

A piston 23 is fixed to the tip of the piston rod 1, and a spherical check valve 15 and a spring 25 that slightly urges the spherical check valve 15 inward are provided within the piston 23. Pistonshi 2
3 is slidably inserted in the cylinder 16 filled with brake fluid 26 in the axial direction. A portion of the outer periphery of the cylinder 16 is cut in the axial direction to form a bypass 18 when inserted into the housing 11. The throttle valve 19 is provided with a pore 20,
A V-shaped groove is eccentrically carved on the outer periphery of the pore 20. This throttle valve 19 is inserted into the cylinder 16, and the flow rate of the brake fluid 26 flowing out from the small hole 17 provided on the side surface of the cylinder 16 is controlled by the space formed by the V-shaped groove and the inner wall of the cylinder 16. Adjustment is possible by rotating the throttle valve.

As shown in FIG. 5, the diaphragm 4 has a thin cylindrical large diameter diaphragm portion 7 corresponding to the inner diameter of the housing 11 and a thin wall corresponding to the outer diameter of the piston rod 1 which is connected via a thick rib 5. A cylindrical small-diameter diaphragm portion 6 and annular beads 9 and 8 each having a thickness greater than the thickness of the diaphragm 4 are provided at the end of each diaphragm portion.

Next, the state of connection between the piston rod 1 and the diaphragm 4 will be explained with reference to FIG. A diaphragm mounting bead 8 is brought into close contact with the groove 2 of the piston rod 1, and a diaphragm retaining collar 10 is inserted around the outer periphery of the bead 8, thereby serving as a seal and fixing the piston rod. This diaphragm retaining collar 10 is fitted at part 3 of the piston rod by press-fitting or adhesive.

The constriction of the piston rod 1, the corner of the piston rod 1 that contacts the diaphragm at the groove 2, and the end of the diaphragm retaining collar 10 are formed into smooth arc shapes so as not to be damaged even if the diaphragm 4 is operated repeatedly. . Also, the outer diameter from the constriction of the piston rod 1 to the groove 2 is such that the diaphragm 4 is
The diameter is reduced by the thickness of the film.

FIG. 4 is a diagram showing a state in which the housing 11 and the diaphragm 4 are connected. The inner diameter of the housing 11 is large at the portion into which the cylinder 16 is inserted. After the diaphragm 4 and piston rod 1 are attached, the housing attachment bead 9 is fitted into the groove of the diaphragm attachment collar 14, and the housing is attached. 11 from the large diameter side and press it against the stepped part.
After inserting the cylinder 16 and throttle valve 19 via the wave washer 15, they are screwed to the housing 11 with nuts 21. At this time, a wave washer 15 is inserted to prevent changes in the tightening strength of the housing mounting bead due to differences in dimensional accuracy of the housing 11, cylinder 16, throttle valve 19, etc. Again, diaphragm 4
In order to avoid damaging the diaphragm 4, the corner portions of the stepped portion of the housing 11 and the groove portion of the diaphragm mounting collar 14 that contact the diaphragm 4 are formed into smooth arc shapes.

In the air space separated by the diaphragm 4, a diaphragm guide 28, which has one end in contact with the collar 5 of the diaphragm 4 and is held by the small diameter diaphragm part 6 and the large diameter diaphragm part 7, is connected to the housing 11.
and the outer diameter of the piston rod 1, and is inserted so as to be slidable in the axial direction.

Between the diaphragm guide 28 and the bearing 30,
When the external force applied to the piston rod 1 is removed, a coil spring 29 is inserted to the extent that the piston rod 1 is stopped at that position, and urges the diaphragm 4 in a direction to compress it. Further, the housing 11 is provided with a port 12 for sending compressed air into the air space as a return mechanism for the piston rod 1, and a packing 31 is inserted between the piston rod 1 and the bearing 30 to prevent compressed air from leaking. There is.

Next, the operation of the embodiment of the present invention will be explained mainly with reference to FIGS. 2, 6, and 7. 6 and 7 are diagrams showing the operating states of the diaphragm, with FIG. 6 showing the normal state and FIG. 7 showing the state where the piston rod 1 is pushed in to the maximum extent.

When a load is applied to one end of the piston rod 1, the spherical check valve 24 is closed by the pressure of the spring 25 and the brake fluid 26, and the brake fluid 26 in the cylinder 16 passes through the small hole 20 of the throttle valve 19 and the small hole 17 of the cylinder. Then, it flows into the bypass 18 and flows to the rear of the piston. This leaked brake fluid 26 is transferred to the coil spring 29
Against the biasing force of the liquid, an amount equivalent to the volume of the piston rod entering the cylinder 16 flows toward the diaphragm 4, forming a reservoir 27. When the load is removed, compressed air is sent through the port 12 to quickly return the piston rod 1 to its original position, and the brake fluid in the fluid reservoir 27 is pressed, opening the spherical check valve 24 and opening the cylinder 16. The piston 23 and the piston rod 1 are quickly returned to their original positions.

Next, when the diaphragm 4 changes the size of the fluid reservoir 27 as the braking fluid increases or decreases, the thin film of the diaphragm 4 creates a space where low pressure air A ring of arcuate protrusions (when viewed in cross section) is formed so that the surface area is minimized on the space side. The thin film of the diaphragm 4 is then moved from the diaphragm guide 28 side to the piston rod 1 or housing 11 side (moved from FIG. 6 to FIG. 7), or from the housing 11 or piston rod 1 side to the diaphragm guide 28 side (see FIG. 7). (moved from Figure 6) and moves smoothly as if rolling, without sliding or friction. When returning the piston rod 1 with compressed air, the compressed air applies equal pressure in all directions, so make sure that there is no compressed air between the diaphragm guide 28 and the diaphragm 4, and between the diaphragm guide 28, the piston rod 1, and the housing 11. The thin film of the diaphragm 4 forms a ring of arcuate protrusions (when viewed in cross section), and the liquid pool 2
In order to ensure smooth movement of the diaphragm 4 due to the change in 7, the diaphragm 4 is weakly biased by a coil spring 29.

The feed rate of the piston rod 1 can be set by adjusting the throttle valve 19 with the knob 22 as described above.

Further, when returning the piston rod to its original position, if it is desired to return the piston rod to its original position quickly after the load is removed, depending on the purpose of use, compressed air may be constantly fed through the port 12. Also, if you want to keep it stationary at that position after removing the load, use port 12.
It is only necessary to open the piston to the atmosphere, and after the operation is completed, compressed air can be sent through the port 12 to quickly return the piston to its original position.

FIG. 8 is a reference diagram showing an example of use of the device of the present invention. FIG. 9 is an explanatory diagram showing the working process.
Figure 8 shows an example in which the tip of the drill is used in a drilling machine.Until the tip of the drill comes into contact with the cutting object, it is moved quickly with an air cylinder, but the feed rate during cutting is
The speed is controlled by a speed control device to an appropriate value depending on various conditions.

With cutting machines such as drilling machines, there is a limit to the depth that can be cut in one operation due to factors such as cooling the frictional heat generated during cutting and removing cutting debris, and in the case of deep holes, it may be necessary to repeat the process several times. Figure 9, a~
d).

With a speed control device, the piston rod returns to its original state when the load is removed, and the piston rod returns to its original state immediately when the load is removed. The feed l to the cutting part b is also at the same speed as the feed during cutting, resulting in poor working time efficiency. If the piston rod remains stationary at that position even after the load is removed, as in the device of the embodiment of the present invention, the cut position will move quickly and cutting can be started immediately, and after the work is finished, compressed air will Since it can quickly return to its original position, work time can be significantly reduced.

As described above in detail, the configuration of the present invention provides the following effects.

The provision of annular beads at both ends of the diaphragm facilitates connection to the piston rod and housing and provides a complete seal.

In addition, the coil spring that biases the diaphragm guide is weakened, forcing the diaphragm guide toward the diaphragm and creating a small pressure on the brake fluid through the diaphragm collar. This pressure brings the diaphragm, diaphragm guide, piston rod, and housing into close contact, and generates an arcuate protrusion ring (when viewed in cross section) in the gap between the diaphragm guide, piston rod, and housing, allowing the diaphragm to move smoothly in a rolling manner. It became possible. In addition, because the coil spring is weak, the piston rod remains at that position when the load is removed, so it can now be used in devices that repeatedly stop work.

Furthermore, since the return mechanism uses a combination of a weak spring and compressed air, the piston rod can be quickly returned to its original position.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the diaphragm part of a conventional device, Fig. 2 is a structural diagram showing an embodiment of the present invention, and Fig. 3 is a schematic diagram showing the diaphragm part of a conventional device.
The figure is a partial cross-sectional view showing the method of connecting the piston rod and the diaphragm, FIG. 4 is a partial cross-sectional view showing the method of connecting the housing and the diaphragm, FIG. 7 are diagrams showing the operating states of the diaphragm of the embodiment of the present invention, FIG. 6 is in the normal state, and FIG.
The figure shows the state in which the piston rod is pushed in to the maximum extent, FIG. 8 is a reference view showing an example of the use of the apparatus according to the present invention, and FIG. 9 is an explanatory view showing the working process. 1...Piston rod, 2...Groove, 4...Diaphragm, 5...Brim, 6...Small diameter diaphragm part, 7...Large diameter diaphragm part, 8...Rod mounting beat, 9...Housing mounting beat, 1
0...Diaphragm holding collar, 11...Housing, 12...Port, 14...Diaphragm mounting collar, 15...Wave washer, 16...
Cylinder, 17... Small hole, 18... Cylinder bypass, 19... Throttle valve, 20... Small hole, 21...
Nut, 22...knob, 23...piston, 24
... Spherical check valve, 25 ... Spring, 26 ... Braking fluid, 27 ... Liquid reservoir, 28 ... Diaphragm guide, 29 ... Coil spring, 30 ... Bearing, 31
...Patsukin.

Claims (1)

[Scope of utility model registration request] In a piston cylinder type braking device of the type in which a space in which the brake fluid flows and an air space in the cylinder housing are separated by a flexible approximately cylindrical diaphragm, the diaphragm is a thin film cylindrical large diameter diaphragm corresponding to the inner diameter of the housing. and a thin cylindrical small diameter diaphragm part corresponding to the outer diameter of the piston rod connected to the cylindrical part via a thick rib, and a thin film cylindrical small diameter diaphragm part corresponding to the outer diameter of the piston rod, which is thicker than the wall thickness of the diaphragm at the end of each diaphragm part. annular beads are provided, and the beads of the large diameter diaphragm portion and the small diameter diaphragm portion are each airtightly fixed to the cylinder housing and the piston rod with mounting collars,
A diaphragm guide is provided in the air space and is pressed against the diaphragm in the axial direction by a spring sufficient to stop the piston rod at that position when the external force applied to the piston rod is removed, thereby forming the air space. 1. A feed rate control device, characterized in that an opening is provided in said cylinder housing, and compressed air is introduced into said cylinder housing to return said piston rod.