WO2018078791A1 - Coaxial pipe assembling bush - Google Patents

Abstract

Provided is a coaxial pipe assembling bush used to integrally coaxially assemble a plurality of pipes, wherein a cylindrical section has formed therein one or more flow passages connecting the opposite axial ends thereof, the cylindrical section being configured such that, while an outer pipe and an inner pipe are arranged coaxially, the cylindrical section comes in contact with the inner surface of the outer pipe and with the outer surface of the inner pipe to make the distance between both the surfaces constant circumferentially.

Description

Bushings for assembling coaxial pipes

The present invention relates to a bush for assembling a coaxial pipe used for integrally assembling a plurality of pipes coaxially.

There is a configuration in which a plurality of pipes having different diameters are coaxially stacked, and a fluid having a circular cross section in the center or a circular cross section formed between the pipes is made to flow fluid such as air. . Such a configuration is found, for example, in a chuck device used in a machine tool. In such a chuck device, a pipe for supplying coolant or air is assembled in a spindle that transmits rotation. The following Patent Document 1 discloses a configuration in which a coolant supply path is provided in a spindle, and a coolant pipe is inserted into a cylindrical spindle. Specifically, a spindle as a rotating body is assembled via a bearing, and a coolant pipe therein is connected to an intermediate rod or the like in the axial direction via a bush so that the central axis is aligned with the central axis of the spindle. Is assembled.

Japanese Patent Laid-Open No. Sho 62-039154

In the conventional chuck device, the coolant pipe for passing the coolant through the spindle is coaxially arranged. For example, in the case of the chuck device for detecting the seating of the gripped workpiece, an air pipe for passing air further is provided. It becomes the structure assembled | attached coaxially with a coolant pipe. In such an assembly structure composed of a plurality of pipes, an inner pipe with a small diameter is inserted into an outer pipe with a large diameter, arranged coaxially by cantilever support, and then the free end side is integrated by fitting a receiving member. Fixed to. However, the pipe supported on the cantilever is bent, and the center position of the pipes on the free end side, that is, the fitting side may be shifted. In such a case, an assembling operation for fitting the receiving member without providing a gap with respect to the plurality of pipes not maintaining the coaxial state becomes very difficult.

Therefore, an object of the present invention is to provide a bush for assembling a coaxial pipe for integrally assembling a plurality of pipes coaxially in order to solve such a problem.

A bush for assembling a coaxial pipe according to an aspect of the present invention is a cylinder for contacting the inner side surface of an outer pipe and the outer side surface of the inner pipe that are coaxially arranged to make the distance between both surfaces constant and circumferential. One or two or more flow paths that connect both axial ends are formed in the shape portion.

According to the assembly bushing having the above-described structure, the cylindrical portion is inserted between the outer pipe and the inner pipe arranged coaxially, and the plurality of pipes are arranged coaxially. It becomes easy to assemble by etc. And since the flow path is formed in the cylindrical part of the assembly bushing located between the pipes arrange | positioned coaxially, the fluid which flows through the inside of a pipe can also be passed.

It is the partial cross section figure which showed the principal part of the chuck device. It is the figure which showed the state which attaches a workpiece | work receiving part to a some coaxial pipe. It is the expanded sectional view which showed the coolant pipe arrange | positioned coaxially and the 1st and 2nd air pipe. It is the figure which showed the axial direction end surface of the bush for an assembly | attachment. It is the figure which showed the axial direction end surface of the 1st modification of the bush for an assembly | attachment. It is sectional drawing which showed the 2nd modification of the bush for an assembly | attachment.

Next, an embodiment of a bush for assembling a coaxial pipe according to the present invention will be described below with reference to the drawings. In the present embodiment, an assembly bush used for a chuck device of a machine tool will be described. FIG. 1 is a partial cross-sectional view showing the main part of the chuck device. This chuck device 1 constitutes a spindle chuck of a machine tool. In a machine tool, a rotary motion is given to a work held by the spindle chuck, and cutting or the like is performed with a tool.

In the chuck device 1, air is sent to the seating surface of the work gripped by the chuck claws, and seating confirmation is performed by detecting the air pressure. Moreover, at the time of a process, a coolant is sprayed on the process point of the workpiece | work with which the tool was applied, and the washing | cleaning of the chip produced by cooling with respect to a workpiece | work or a process is performed. Therefore, a plurality of pipes for passing air and coolant are coaxially assembled to the chuck device 1. The configuration of the coaxial pipe described in the present embodiment is merely an example, and the bushing for assembling the coaxial pipe can be applied to a structure other than the chuck device described in the present embodiment.

In the chuck device 1 shown in FIG. 1, a spindle 11 is rotatably provided inside a cylindrical spindle stock via a bearing, and a chuck opening / closing mechanism 12 is assembled at an end thereof. The spindle 11 is adapted to transmit the rotation of the spindle motor via a timing belt. A chuck opening / closing mechanism 12 is assembled to the spindle 11 at the end in the axial direction so that a workpiece to be processed can be gripped. Accordingly, the rotation is transmitted to the chuck opening / closing mechanism 12 via the spindle 11 whose rotation is controlled, and the gripped workpiece is given rotation during processing.

The chuck device 1 is provided with a chuck cylinder for driving the chuck opening / closing mechanism 12. The chuck cylinder is, for example, a double rod type air cylinder, and a connected draw bar 13 is inserted into the spindle 11 and connected to a drive transmission rod 14 of the chuck opening / closing mechanism 12. The chuck opening / closing mechanism 12 of this embodiment is a pin arbor chuck, and a pin arbor 15 is engaged with an annular projecting portion 141 formed on the drive transmission rod 14. Therefore, the axial movement of the drive transmission rod 14 is converted into the sliding of the pin arbor 15 in an oblique direction, and the chuck claws 16 of the three pin arbors 15 are opened and closed in the radial direction.

In the chuck device 1, the draw bar 13 and the piston rod of the cylinder are cylindrical rods, and a plurality of pipes through which coolant and air flow are inserted coaxially. In the present embodiment, a coolant pipe 21 having a minimum diameter is disposed on the center side, and two first and second air pipes 22 and 23 having different diameters are disposed on the outside thereof. Here, FIG. 3 is an enlarged cross-sectional view showing end portions of the coolant pipe 21 and the first and second air pipes 22 and 23. A coolant flows in the coolant pipe 21, and air flows between the coolant pipe 21 and the first air pipe 22 and between the first and second air pipes 22 and 23.

The coolant pipe 21 and the first and second air pipes 22 and 23 are arranged coaxially, and the end of the coolant pipe 21 protrudes most toward the chuck opening / closing mechanism 12 side (the right side in the drawing), and the first is arranged outside. The end portions of the first and second air pipes 22 and 23 are formed in such a length that they are sequentially retracted. This is a configuration that facilitates the fitting operation when the coolant pipe 21 and the first and second air pipes 22 and 23 are fitted into the receiving block 25 as shown in FIG. 2 is a view corresponding to FIG. 1 and shows a state in which the work receiving portion 121 of the chuck opening / closing mechanism 12 is assembled.

The ends of the coolant pipe 21 and the first and second air pipes 22 and 23 are located at the end of the drive transmission rod 14. On the other hand, the receiving block 25 is formed by changing the inner diameter of the through hole 250 in a stepped manner in accordance with the outer diameters of the coolant pipe 21 and the first and second air pipes 22 and 23. Therefore, when the workpiece receiving portion 121 is moved and assembled in the direction indicated by the arrow, the coolant pipe 21 and the first and second air pipes 22 and 23 are inserted into the through hole 250 of the receiving block 25 with almost no gap. It is.

In FIG. 3, the shape of the through hole 250 of the receiving block 25 at the time of such assembly is shown by a one-dot chain line. At the time of inlay to the receiving block 25, as shown in the drawing, the corresponding coolant pipe 21 and the first and second air pipes 22, 23 with respect to the first to third inner peripheral portions 251, 252, 253 in the through hole 250, Are inserted almost simultaneously. Therefore, if the coolant pipe 21 and the first and second air pipes 22 and 23 are not all arranged coaxially, one of the pipes is caught by the stepped portion in the through hole 250 and cannot be inserted.

In the chuck device 1, the receiving block 25 is assembled on the free end side of the cantilevered coolant pipe 21 and the first and second air pipes 22 and 23, so that the free end side is not coaxial due to the bending of each pipe. A condition can arise. Even if it is attempted to inlay a plurality of pipe tips simultaneously with respect to the receiving block 25 in such a state, there is not enough room for the dimensions, and the assembling work becomes very difficult. Therefore, in the present embodiment, a configuration is adopted in which the coaxial state of the coolant pipe 21 and the first and second air pipes 22 and 23 is maintained, and the assembly can be easily performed.

The coolant bush 21 and the first and second air pipes 22 and 23 are fitted with assembly bushings 27 and 28 for maintaining the coaxial state of each other. That is, as shown in FIG. 3, an assembly bush 27 is fitted between the coolant pipe 21 and the first air pipe 22, and an assembly bush 28 is fitted between the first and second air pipes 22 and 23, respectively. It is. Here, FIG. 4 is a diagram showing an axial end surface (the left end surface shown in FIG. 3) of the assembly bushing 27.

The assembling bush 27 has a cylindrical portion 31 having a constant thickness in the radial direction according to the inner diameter dimension matching the outer diameter dimension of the coolant pipe 21 and the outer diameter dimension matching the inner diameter dimension of the first air pipe 22. A plurality of flow paths 32 penetrating in the axial direction with respect to the cylindrical portion 31 are formed. The flow path 32 is a through-hole having a circular cross section, and is formed at equal intervals in the circumferential direction of the cylindrical portion 31. Since air flows between the coolant pipe 21 and the first air pipe 22, the flow path 32 of the assembly bushing 27 is a flow path for passing the air.

On the other hand, the assembling bush 28 has the same configuration as the assembling bush 27 except for the size. That is, since air flows between the first and second air pipes 22 and 23, the flow path 36 of the cylindrical portion 35 constituting the assembly bushing 28 is also an air flow path. The cylindrical portions 31 and 35 of the assembling bushes 27 and 28 are formed with hooking portions 33 and 37 having enlarged diameters at their ends, and are positioned at the ends of the first air pipe 22 and the second air pipe 23. It has come to be applied for.

Therefore, the assembly bushings 27 and 28 are inserted into the free end portions of the coolant pipe 21 and the first and second air pipes 22 and 23 inserted in layers. In particular, the assembly bushings 27 and 28 function as spacers that keep the gap between the pipes constant so as to contact the inner surface of the outer pipe and the outer surface of the inner pipe. Therefore, the coolant pipe 21 and the first air pipe 22 are arranged coaxially by the assembly bushing 27, and the first air pipe 22 and the second air pipe 23 are arranged coaxially by the assembly bushing 28. Thus, all three pipes 21, 22, and 23 are arranged coaxially.

Therefore, as shown in FIG. 2, when the through hole 250 of the receiving block 25 is fitted into the coolant pipe 21 and the first and second air pipes 22, 23, as shown in FIG. The corresponding coolant pipe 21 and the end portions of the first and second air pipes 22 and 23 are inserted into the corresponding locations almost simultaneously with respect to the first to third inner peripheral portions 251, 252, and 253. That is, even if the three pipes 21, 22, and 23 are bent, since they are maintained in a coaxial state, the operator can connect the through-hole 250 of the receiving block 25 with the three pipes 21, 22, and 22. 23 can be aligned at a time, and thus can be easily fitted. The assembled bushes 27 and 28 after assembly remain in the chuck device 1 as they are, but since air flows through the flow paths 32 and 36, the seating detection of the workpiece is not affected. .

Next, a modification of the assembly bush will be described. FIG. 5 is a view showing an axial end surface of the first modification of the assembly bushing. In this assembling bush 41, a plurality of channel-shaped channels 43 are formed so that both ends in the axial direction pass through a cylindrical portion 42 in contact with the inner surface of the outer pipe and the outer surface of the inner pipe. . The groove-shaped channels 43 are grooves having a rectangular cross section formed on the inner peripheral surface side of the cylindrical portion 42, and are formed at equal intervals in the circumferential direction. A hook portion 44 having an enlarged diameter is formed at one end portion of the cylindrical portion 42.

FIG. 6 is a cross-sectional view showing a second modification of the assembly bushing. The assembly bushing 51 is formed by a thick cylindrical portion 52 that is in contact with the inner surface of the outer pipe and the outer surface of the inner pipe, like the assembly bush 27. A hook portion 53 having an enlarged diameter is formed at one end of the cylindrical portion 52, and a thread groove channel 54 is formed on the inner peripheral surface. In particular, the thread groove channel 54 has a double thread configuration, and is one thread groove that is spirally continuous from one end to the other end of the cylindrical portion 52.

These assembling bujus 41 and 51 are also inserted between the outer pipe and the inner pipe and can serve as spacers to arrange both pipes coaxially. After assembly, the assembly bushes 41 and 51 remain in the pipe, but the fluid flowing in the pipe can be passed through the groove-shaped channel 43 and the thread channel 54. Further, the assembly bushings 27, 28, 41, 51 of the present embodiment are formed of steel, resin, rubber, or the like. The dimensions are, for example, a thickness of 2 mm and an inner diameter of about 13 mm or 20 mm. Therefore, when forming a flow path in such a small component, the groove-shaped flow path 43 and the thread groove flow path 54 are easy to process, and in particular, the thread groove flow path 54 can be easily processed using a tap or the like. Can do.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to these, A various change is possible in the range which does not deviate from the meaning.
For example, although the flow paths are formed on the inner peripheral surface side of the cylindrical portion in the assembly bushes 41 and 51, they may be formed on the outer peripheral surface side.
Further, the bush for assembly has been described by showing a cylindrical pipe, but it may be for a square pipe.

DESCRIPTION OF SYMBOLS 1 ... Chuck apparatus 12 ... Chuck opening / closing mechanism 13 ... Draw bar 21 ... Coolant pipe 22 ... 1st air pipe 23 ... 2nd air pipe 25 ... Receiving block 27, 28 ... Assembly bush 31 ... Cylindrical part 32 ... Flow path 33 ... Hook Part

Claims (4)

1. One or two or more streams that connect both ends in the axial direction to a cylindrical portion that is in contact with the inner side surface of the outer pipe and the outer side surface of the inner pipe that are coaxially arranged, and to keep the distance between the two surfaces circumferentially constant. Bushings for assembling coaxial pipes with paths.
2. 2. The bushing for assembling a coaxial pipe according to claim 1, wherein the flow path is a hole or a groove penetrating the cylindrical portion in the axial direction.
3. The bush for assembling a coaxial pipe according to claim 1, wherein the flow path is a thread groove formed in the cylindrical portion.
4. The cylindrical portion is a bushing for assembling a coaxial pipe in which a hook portion extending radially inward or outward is formed at one axial end portion.
   
   
   
   

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