JPH0569643B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to an ultrasonic vibration broach used for simultaneously finishing both sides of an internal groove provided on the inner surface of a workpiece, and an ultrasonic vibration broach. Regarding machining methods, ultrasonic vibration is particularly suitable for finishing precision grooves on workpieces that have low rigidity in the groove width direction and are relatively thin in the cutting direction, such as vane grooves on rotary compressor cylinders. The present invention relates to a broach and an ultrasonic vibration broaching method using this ultrasonic vibration broach.

[Background of the invention]

Conventionally, the internal grooves of workpieces have been efficiently finished using a broach, but this is especially true for workpieces with low rigidity in the groove width direction, such as rotary compressor cylinders with vane grooves formed on the internal surface. In the case of a material, the cutting resistance causes the workpiece to be elastically deformed in the groove width direction, resulting in deterioration of the shape accuracy and dimensional accuracy of the groove.

In order to prevent this accuracy deterioration, for example, as described in Japanese Utility Model Publication No. 53-9999, a presser with a sharp tip is inserted into the upper and lower surfaces of the workpiece near the machining groove. A method of suppressing elastic deformation during processing of a cut object is known.

However, this method requires a special jig to apply strong pressure to the workpiece, and dents and bulges remain on the upper and lower surfaces of the workpiece to which the presser is pressed, and these must be removed. There have been problems such as the need for a post-process for the recess, and the need to add machining allowance to the workpiece in advance by an amount corresponding to the thickness corresponding to the recess.

As a solution to these problems, by reducing the cutting force, the elastic deformation of the workpiece during machining can be reduced, and high precision can be obtained without using a special pressure device for the workpiece. .

It is widely recognized that ultrasonic vibration cutting is extremely effective as a method of reducing cutting resistance.
An example of its application to a brooch can be found in Japanese Patent Publication No. 36-20186. This method will be explained using FIG. 12.

FIG. 12 is a schematic diagram of broaching using a conventional ultrasonic vibration broach.

This ultrasonic broach is equipped with a screw at the right end of the broach 1, and the broach 1 is attached to the tip of a vibration horn 2 for amplifying the amplitude of several microns of longitudinal vibration (direction 4a) of an ultrasonic vibration source 3. It is fastened with the screws mentioned above. The broach 1 is provided with cutting edges only at portions A, B, C, and D, which are the antinodes of longitudinal vibration, to reduce cutting resistance. 6 is a workpiece, 5 is a broach support device, 4b is a broach 1
is the feeding direction.

However, this method had the following problems.

(1) There is no cutting edge near the node of longitudinal vibration, and if the number of cutting edges is the same as a conventional broach, the broach length will be longer.

(2) A special broach support device 5 is required at the node of the broach 1 on the side opposite to the ultrasonic vibration drive source 3.

(3) A powerful ultrasonic oscillator is required to drive the long broach 1.

In addition, since the vibration horn 2 and the broach 1 are strongly connected by the screw in order to transmit ultrasonic waves efficiently, the broach 1
Another problem was that the broach 1 had to be uncoupled from the vibrating horn 2, the machined work piece 6 removed, and then the broach 1 had to be returned to the position before machining. If the broach 1 is returned to its original position without removing the workpiece 6, the cutting blade will skim over the finished surface of the workpiece 6, and the quality of the finished surface will deteriorate due to biting of chips from the flank of the cutting blade. There were problems such as a decrease in the cutting edge and a deterioration in the life of the cutting edge, which hindered the practical use of this type of ultrasonic broach.

[Purpose of the invention]

The present invention solves the problems of the prior art as described above, and makes it possible to precisely finish both sides of the inner groove of a workpiece having a groove on the inner surface and having low rigidity in the width direction of the groove. The purpose of the present invention is to provide an ultrasonic vibration broach with a simple structure and an ultrasonic vibration broaching method using this ultrasonic vibration broach.

[Summary of the invention]

The structure of the ultrasonic vibrating broach according to the first invention is that in the ultrasonic vibrating broach used for simultaneously finishing both sides of an inner groove formed on the inner surface of a workpiece, the ultrasonic vibrating broach is , a guide portion to the inner groove of the workpiece, and a plurality of pairs or a pair of cutting blades are arranged on side surfaces opposite to both side surfaces of the inner groove so that the thickness gradually increases gradually toward the base portion. A broach is attached to the tool holder at the base of the broach, which has a cutting edge and a parallel part that is slightly longer than the thickness of the workpiece in the cutting direction and passes through the inner groove finished with the cutting edge. An ultrasonic broaching tool inserted and fixed into the slit is attached to one end of the ultrasonic vibrator in the ultrasonic vibration direction,
Further, the cutting edge is screwed to the tip of the vibrating horn fixed at a node of ultrasonic vibration so that the cutting edge is located at the antinode of the ultrasonic vibration closest to the node.

The structure of the ultrasonic vibration broach according to the second invention is that in the ultrasonic vibration broach used for simultaneously finishing both sides of an inner groove formed on the inner surface of a workpiece, the ultrasonic vibration broach is , a guide portion to the inner circumferential groove of the workpiece, which is slightly longer than the thickness of the workpiece in the cutting direction; and a plurality of pairs, or a pair of An ultrasonic broaching tool is prepared by inserting and fixing a broach having a cutting edge on both sides of the inner groove and a cutting edge portion disposed on the opposite side surface at the base into a slit in a tool holder. The cutting edge is located at the antinode of the ultrasonic vibration closest to the tip of a vibration horn that is attached to one end of the child in the ultrasonic vibration direction and is fixed at a node of the ultrasonic vibration. It was screwed together in this way.

The configuration of the ultrasonic vibration broaching method according to the third invention is that in the ultrasonic vibration broaching method in which both sides of an internal groove formed on the inner surface of a workpiece are simultaneously finished, the process is performed sequentially from the tip to the base. , a guide part for the inner groove of the workpiece, and a plurality of pairs or a pair of cutting blades arranged on the side faces opposite to both sides of the inner groove so that the thickness gradually increases gradually toward the base part. A broach is fixed to the tool holder at the base portion, and the broach is provided with a parallel portion that is slightly longer than the thickness of the workpiece in the cutting direction and passes through the inner groove finished by the cutting edge. An ultrasonic broaching tool made of Using a screw-fastened ultrasonic vibrating broach with the cutting edge positioned close to the antinode of ultrasonic vibration, first cut the workpiece below the broach, which is disposed with the tip facing down. After locating the inner groove of the object and sending the ultrasonically vibrating broach downward to finish machining both sides of the inner groove with the cutting edge, the cutting edge has completely come out of the inner groove downward. , stopping the broach feeding and stopping the ultrasonic vibration, and moving the workpiece relative to the broach in a direction perpendicular to the cutting direction to remove the broach from the inner groove;
The broach is raised and separated from the workpiece.

The configuration of the ultrasonic vibration broaching method according to the fourth invention is that in the ultrasonic vibration broaching method in which both sides of an internal groove formed on the inner surface of a workpiece are simultaneously finished, the process is performed sequentially from the base to the tip. , a guide portion to the inner groove of the workpiece, which is slightly longer than the thickness of the workpiece in the cutting direction; and a plurality of pairs or a pair of cutting portions with the thickness gradually increasing toward the tip. An ultrasonic broaching tool comprising a broach having a cutting edge disposed on both sides of the internal groove and a cutting edge disposed on the opposite side is fixed to a tool holder at the base, and the ultrasonic broaching tool is To the tip of a vibrating horn that is attached to one end side in the vibration direction and fixed at a portion that becomes a node of ultrasonic vibration, the cutting edge portion is located at the antinode of the ultrasonic vibration closest to the node, Using a screw-fastened ultrasonic vibration broach, first place the broach with its tip facing up, and connect the broach to the internal groove of the workpiece so that its cutting edge fits into the internal hole provided. The workpiece is inserted so as to protrude from the upper surface of the broach, the workpiece is moved relative to the broach in a direction perpendicular to the cutting direction, and its guide part is inserted into the inner groove, and then sending the sonic-vibrating broach downward to finish both sides of the inner groove with the cutting edge;
It is designed so that it can be pulled out downward and removed from the workpiece.

More specifically, by making the ultrasonic vibrating broach have a cutting edge only near the antinode of the longitudinal vibration closest to the ultrasonic vibrator and having a broach length of about 1/4 wavelength or less, the ultrasonic vibrating broach can be bent. The rigidity can be increased, and even if the cross section perpendicular to the direction of vibration has an asymmetric shape, ultrasonic vibration can be generated, and cutting resistance can be reduced. Therefore, even if the workpiece has low rigidity, it is possible to perform high-precision machining of the inner surface or groove without using a special high-pressure jig.

[Embodiments of the invention]

Examples will be explained below.

FIG. 1 is a sectional view of essential parts showing a first embodiment of an ultrasonic vibration broach according to the first invention, and FIG.
FIG. 3 is a perspective view showing the details of the ultrasonic broaching tool in FIG. 1, FIG. It is a perspective view which shows the cylinder for rotary compressors which has a vane groove and is finished-processed by the ultrasonic vibration broach based on the figure.

The ultrasonic vibration broach of this embodiment has a vane groove 21 in the cutting direction that is formed by a pre-processed broach or by sintering and has a groove width B slightly narrower than the required dimension, as shown in FIG. thickness h
This is used for finishing the vane groove 21 of the rotary compressor cylinder 20 related to the workpiece.

First, the ultrasonic broaching tool will be explained using FIG. 2.

12 is a brooch, and this brooch 12
has a guide portion 14, a cutting edge portion 13, and a parallel portion 9 in this order from the tip to the base. That is, 1
4 is a guide portion to the vane groove 21 which is very slightly narrower than the groove width B of the vane groove 21 of the rotary compressor cylinder 20, and 13 is a guide portion whose thickness gradually increases very slightly toward the base. Multiple pairs of cutting blades 13a
(The maximum thickness is T) is a cutting edge portion 9 disposed on the side surface opposite to both side surfaces of the vane groove 21. The length H is slightly longer than the thickness h in the direction
It is a parallel part with a high wear resistance and is made of cemented carbide with high wear resistance. 11 is a tool holder, and the broach 12 is inserted into the slit 15 of this tool holder 11.
The ultrasonic broaching tool 19 is constructed by inserting and fixing them by brazing or gluing.

Next, an ultrasonic vibration broach equipped with the ultrasonic broaching tool 19 configured as described above will be explained with reference to FIG.

3A is an ultrasonic vibrator, and 2 is attached to one end side of the ultrasonic vibrator 3A in the ultrasonic vibration direction, and is slidable by a main shaft sliding guide 8 at a portion that becomes a node of ultrasonic vibration. The main shaft 7 held in
This is a vibrating horn fixed by a fixed flange 10, and the above-mentioned ultrasonic broaching tool 19 is attached to the tip of the vibrating horn 2, and a cutting edge 13 is attached to the antinode of the ultrasonic vibration closest to the node. The contact surface 17 is brought into contact with the vibrating horn 2 and screwed together so that the cutting edge 13 is located at a position λ/4 (FIG. 3) from the node.

An embodiment of the ultrasonic vibration broaching method according to the third invention will be described using the ultrasonic vibration broach constructed as described above.

FIG. 5 is for explaining an embodiment of the ultrasonic vibration broaching method according to the third invention, and the vane groove of the rotary compressor cylinder according to FIG. FIG. 3 is a sectional view of a main part showing a finishing process using an ultrasonic vibration broach.

First, the rotary compressor cylinder 20 is mounted and fixed on the workpiece fixing jig 23. The vane groove 21 of the rotary compressor cylinder 20 is positioned below the broach 12 of the ultrasonic vibration broach (Fig. 5a).

When the ultrasonic vibration broach is turned on, the ultrasonic vibrator 3A is driven, and the ultrasonic vibration broach generates longitudinal vibration whose displacement amplitude is shown in FIG. The portion 13 vibrates as an antinode. And this ultrasonic vibration brooch is
It is sent downward by a hydraulic cylinder (not shown), and both sides of the vane groove 21 are finished by the cutting edge 13 of the broach 12. After the cutting edge 13 comes out of the vane groove 21 downward (FIG. 5b), the broach feeding by the hydraulic cylinder stops, and the driving of the ultrasonic vibrator 3A also stops. Then, the workpiece fixing jig 23 is moved forward in a direction perpendicular to the cutting direction by a fixing jig feeding device (not shown), and the broach 12 is removed from the vane groove 21 [fifth
c], the broach 12 is raised by the hydraulic cylinder, detached from the rotary compressor cylinder 20, and returned to its original position. Next, the succeeding new rotary compressor cylinder 20 is transferred to the position shown in FIG. Cylinder 20 for rotary compressor
The vane groove 21 is finished. Thereafter, the same flow of operations is automatically repeated, and when finishing machining of a predetermined number of rotary compressor cylinders 20 is completed, the ultrasonic vibration broach is turned off.

According to the embodiment described above, like the vane groove 21, the broach length is approximately 1/4 on both sides of the rotary compressor cylinder 20, which has small rigidity in the groove width direction.
Since the ultrasonic vibration broaching process is performed using an ultrasonic vibration broach with an extremely short wavelength, the ultrasonic vibration broach has high rigidity, does not require a special broach support device, and has a simple structure. Its manufacturing cost is also reduced. Further, there is an advantage that the ultrasonic oscillator that drives the ultrasonic transducer 3A can also be small.

By performing broaching using this ultrasonic vibration broach, highly accurate groove processing becomes possible. Furthermore, since the broach length is short, the tool rigidity in the direction perpendicular to the cutting direction is increased, and a large cutting force can be applied. Therefore, since the depth of cut per tooth can be increased, it has the effect of exhibiting cutting performance similar to that of a long broach.

Another embodiment will be described.

6 and 7 are perspective views showing second and third embodiments of the ultrasonic broach processing tool for the ultrasonic vibration broach according to the first invention. In each figure, the second
Parts with the same numbers as those in the figures are the same.

In FIG. 6, reference numeral 16 has a slit 18 provided on one side of the broach 12 where the cutting edge 13 is not provided, from the upper surface of the tool holder 11 to below the cutting edge 13 in order to hold the one side. This is a reinforcement part.

The ultrasonic vibration broaching tool 19A configured in this manner has improved rigidity in the direction perpendicular to the cutting direction, so even if an imbalance occurs in the cutting force produced by the cutting edges 13 on the front and back sides, the broach 12 can be elastically deformed. is extremely small, and the perpendicularity of the inner groove finished by this ultrasonic broaching tool 19A is excellent.

According to the embodiment according to FIG. 6 described above, in addition to the effect of the ultrasonic vibration broach according to FIG. 1, the rotary compressor cylinder 20 according to FIG.
Even if the thickness h of the workpiece in the cutting direction is relatively large compared to the groove width B of the vane groove 21 and the length H of the parallel portion 9 of the broach 12 becomes large, The tool rigidity in the direction perpendicular to the cutting direction of the ultrasonic broaching tool 19A does not decrease.
The advantage is that the perpendicularity of the machined surface of the vane groove 21 broached by this ultrasonic broaching tool 19A is extremely excellent.

Further, since the slit 18 of the reinforcing portion 16 prevents the broach 12 from falling in the cutting direction, when the broach 12 is fixed to the tool holder 11, the broach 12 is fixed to the contact surface of the tool holder 11.
A good perpendicularity to 7 is ensured, and the vane groove 2
There is also the effect that the perpendicularity to the cylinder bottom surface 22 of No. 1 is also improved.

In addition, since there is no reinforcing portion on the side surface of the cutting edge 13, the grindstone can be moved in the direction of the cutting edge, and the worn cutting edge 13 can be re-sharpened.

Ultrasonic broaching tool 19B according to FIG.
Since the reinforcing portion 16A is provided from the upper surface of the tool holder 11 to the tip of the broach 11, the tool rigidity is further improved.

8 to 10 are perspective views showing first to third embodiments of an ultrasonic broaching tool for an ultrasonic vibration broach according to the second invention, respectively. In each figure, parts given the same numbers as in FIG. 2 are the same parts.

The ultrasonic vibration broach according to the first invention includes:
The ultrasonic broaching tool 19 or 19A, 19B screwed to the tip of the vibrating horn 2 is used to press the workpiece from above to below to process an internal groove, and according to the second invention. The ultrasonic vibration broach is used to process an internal groove by pulling out an ultrasonic broaching tool (details will be described later) from above to below the workpiece.

Ultrasonic broaching tool 19C according to FIG.
The broach 12A (details will be described later) is inserted into the slit of the tool holder 11 at its base and fixed. The broach 12A has a guide portion 14 and a cutting edge portion 13A in this order from the base to the tip. That is, 14A is a guide portion to the vane groove 21 which is narrower than the groove width B of the vane groove 21 of the rotary compressor cylinder 20 and slightly longer than the thickness h in the cutting direction, and 13A is a guide portion to the vane groove 21 shown in FIG. A plurality of pairs of cutting blades (the maximum thickness is T) are arranged opposite to both side surfaces of the vane groove 21 so that the thickness gradually increases toward the tip. This is the cutting edge located on the side. This ultrasonic broaching tool 19C is installed at the tip of the vibrating horn 2 (Fig. 1) so that the cutting edge 13A is located at the antinode of the ultrasonic vibration closest to the fixed flange 10 (that is, the node of ultrasonic vibration). and then screwed together.

Ultrasonic broaching tool 19D according to FIG.
is an ultrasonic broaching tool 19 according to FIG.
By providing a reinforcing part 16 on one side of the broach 12A of C, which does not have the cutting edge 13A, from the upper surface of the tool holder 11 to below the cutting edge 13A, the reinforcing part 16 holds the one side, thereby improving tool rigidity. This is what I did.

Ultrasonic broaching tool 19 according to FIG.
E is a broach 12A from the top surface of the tool holder 11.
By providing the reinforcing portion 16A up to the tip of the tool, the tool rigidity is further improved.

An embodiment of the ultrasonic vibration broaching method according to the fourth invention will be described using an ultrasonic vibration broach equipped with the ultrasonic broaching tool 19C configured as described above.

FIG. 11 is for explaining one embodiment of the ultrasonic vibration broaching method according to the fourth invention, and the vane groove of the rotary compressor cylinder according to FIG. FIG. 3 is a sectional view of a main part showing a finishing process using an ultrasonic vibration broach equipped with an ultrasonic broaching tool.

First, the rotary compressor cylinder 20 is mounted and fixed on the workpiece fixing jig 23. The inner surface hole 20a of the rotary compressor cylinder 20 is positioned above the broach 12A of the ultrasonic vibration broach (FIG. 11a).

When the ultrasonic vibration broach is turned ON, the ultrasonic vibration broach is raised by a hydraulic cylinder (not shown), and the cutting edge portion 1 of the broach 12A is raised.
3A protrudes from the upper surface of the rotary compressor cylinder 20 [FIG. 11b]. The workpiece fixing jig 23 is moved back in a direction perpendicular to the cutting direction by a fixing jig feeding device (not shown), and the guide portion 14A of the broach 12A is inserted into the vane groove 21 [FIG. 11] c]. The ultrasonic vibrator 3A is driven, and the cutting edge 13A of the broach 12A vibrates as an antinode. And this ultrasonic vibration brooch is
It is sent downward by the hydraulic cylinder, and both sides of the vane groove 21 are cut into the cutting edge 13A of the broach 12A.
Finished by.

According to the embodiment described above, in addition to the effects of the embodiment of the ultrasonic vibration broaching method according to the third aspect of the invention, there are the following effects.

(1) Since the guide portion 14A to the vane groove 21 can be made longer, the vane groove 21 and the ultrasonic broaching tool 19C can be accurately aligned.

(2) Since no guide is required on the tool tip side, the total tool length can be further shortened.

(3) Even if the tool rigidity is small, since it is a tension process, there is no risk that the broach 12A will bend in the buckling direction, and stable broaching can be performed.

In addition, in each of the above embodiments, the brooch 1
Although the material of 2 and 12A is made of cemented carbide, it is not limited to cemented carbide, but can also be made of cermet, CBN sintered material,
Or TiC to the cemented carbide or high speed steel,
It may be coated with a hard film of Ti, Al ₂ O ₃ or the like.

Furthermore, in each of the above embodiments, the cutting edge portion 1
Although 3 and 13A are made up of a plurality of pairs of cutting blades, they may be made up of a pair of cutting blades. However, it goes without saying that the cutting efficiency is improved by using multiple pairs of cutting edges.

〔Effect of the invention〕

As explained in detail above, according to the present invention, the structure has a groove on the inner surface and allows precise finishing of both sides of the inner groove of a workpiece having small rigidity in the width direction of the groove at the same time. A simple ultrasonic vibration broach and an ultrasonic vibration broaching method using this ultrasonic vibration broach can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts showing a first embodiment of an ultrasonic vibration broach according to the first invention, and FIG.
FIG. 3 is a perspective view showing the details of the ultrasonic broaching tool in FIG. 1, FIG. FIG. 5 is a perspective view showing a cylinder for a rotary compressor having a vane groove, which is finished by the ultrasonic vibration broach according to the figure, and FIG. 5 is an embodiment of the ultrasonic vibration broaching method according to the third invention. This is for explaining the vane groove of the rotary compressor cylinder according to Fig. 4.
FIG. 1 is a cross-sectional view of main parts showing the finishing process using the ultrasonic vibration broach according to the first invention, and FIGS. 8 to 10 are perspective views showing the first to third embodiments of the ultrasonic broaching tool for the ultrasonic vibration broach according to the second invention. , 1st
FIG. 1 is for explaining an embodiment of the ultrasonic vibration broaching method according to the fourth invention, in which the vane groove of the cylinder for a rotary compressor according to FIG. FIG. 12 is a cross-sectional view of a main part showing a finishing process using an ultrasonic vibration broach equipped with a sonic broaching tool, and is a schematic diagram of broaching using a conventional ultrasonic vibration broach. 2... Vibration horn, 3A... Ultrasonic vibrator, 9
... Parallel part, 10 ... Fixed flange, 11 ... Tool holder, 12, 12A ... Broach, 13, 1
3A... Cutting blade part, 13a... Cutting blade, 14, 14A
...Guide section, 15...Slit, 16, 16A...
...Reinforcement part, 19, 19A, 19B, 19C, 19
D, 19E...Ultrasonic broaching tool, 20
... Cylinder for rotary compressor, 20a ... Inner hole, 21 ... Vane groove, 23 ... Workpiece fixing jig, B ... Groove width, h ... Thickness of workpiece in the cutting direction.

Claims (1)

[Claims] 1. In an ultrasonic vibration broach used for simultaneously finishing both sides of an inner groove formed on the inner surface of a workpiece, the inner groove of the workpiece is a cutting edge portion having a plurality of pairs or a pair of cutting edges arranged on a side surface opposite to both sides of the inner groove so that the thickness gradually increases toward the base portion; A broach is inserted and fixed into the slit of the tool holder at the base portion, and the broach has a parallel portion that is slightly longer than the thickness in the cutting direction of the workpiece, and passes through the inner groove finished by the cutting edge. An ultrasonic broaching tool is attached to one end of the ultrasonic vibrator in the ultrasonic vibration direction,
Further, the ultrasonic horn is screwed to the tip of a vibrating horn fixed at a node of ultrasonic vibration so that the cutting edge is located at the antinode of the ultrasonic vibration closest to the node. Sonic vibration brooch. 2. Claim 1: A reinforcing portion is provided on one side of the broach that does not have a cutting edge, from the upper surface of the tool holder to the tip of the broach or below the cutting edge. Ultrasonic vibration broach as described in section. 3. In an ultrasonic vibration broach that is used to finish simultaneously both sides of an internal groove formed on the inner surface of a workpiece, from the base to the tip, the broach is slightly longer than the thickness of the workpiece in the cutting direction. , a guide portion to the inner circumferential groove of the workpiece, and a plurality of pairs or a pair of cutting blades facing both sides of the inner circumferential groove so that the thickness gradually increases very slightly toward the tip. An ultrasonic broaching tool, which is formed by inserting and fixing a broach having a cutting edge on a side surface into a slit in a tool holder at the base, is attached to one end side of an ultrasonic vibrator in the ultrasonic vibration direction. , and is characterized in that it is screwed to the tip of a vibrating horn fixed at a node of ultrasonic vibration such that the cutting edge is located at the antinode of the ultrasonic vibration closest to the node. Ultrasonic vibration brooch. 4. Claim 3: A reinforcing part is provided on one side of the broach where there is no cutting edge, for holding the one side from the upper surface of the tool holder to the tip of the broach or below the cutting edge. Ultrasonic vibration broach as described in section. 5. In an ultrasonic vibration broaching method for simultaneously finishing both sides of an internal groove formed on the internal surface of a workpiece, the guide part to the internal groove of the workpiece is formed in order from the tip to the base, and A cutting edge section in which multiple pairs or a pair of cutting edges are arranged on the side surfaces opposite to both sides of the inner groove so that the thickness gradually increases gradually toward the base, and finishing processing is performed using this cutting edge section. An ultrasonic broaching tool is made by fixing a broach to a tool holder at the base part, the broach having a parallel part slightly longer than the thickness of the workpiece in the cutting direction, which passes through the internal groove. The cutting edge is located at the antinode of the ultrasonic vibration closest to the tip of a vibration horn that is attached to one end of the vibrator in the ultrasonic vibration direction and is fixed at a node of the ultrasonic vibration. Using a screw-fastened ultrasonic vibration broach, first position the inner groove of the workpiece below the broach, which is disposed with the tip facing down, and then apply ultrasonic vibration to the The broach is sent downward to finish machining both sides of the inner groove with the cutting edge portion, and after the cutting edge portion has completely come out of the inner groove downward, the broach feeding is stopped and the ultrasonic vibration is stopped. removing the broach from the inner groove by moving the workpiece relative to the broach in a direction perpendicular to the cutting direction;
An ultrasonic vibration broaching method characterized by raising the broach to separate it from the workpiece. 6 In the ultrasonic vibration broaching method in which both sides of an internal groove formed on the inner surface of a workpiece are simultaneously finished, broaching is performed in order from the base to the tip, which is slightly longer than the thickness of the workpiece in the cutting direction. A guide portion to the inner groove of the workpiece, and a plurality of pairs or a pair of cutting blades are arranged on the side faces opposite to both sides of the inner groove so that the thickness gradually increases gradually toward the tip. An ultrasonic broaching tool comprising a broach having a cutting edge fixed to a tool holder at the base is attached to one end side of an ultrasonic vibrator in the ultrasonic vibration direction, and Using an ultrasonic vibration broach screwed onto the tip of the vibrating horn fixed at the point where the cutting edge is located at the antinode of the ultrasonic vibration closest to the node, first Insert the broach, which is placed facing upward, into an inner hole provided in connection with the inner groove of the workpiece, with its cutting edge protruding from the upper surface of the workpiece, and After the workpiece is moved relative to the broach in a direction perpendicular to the cutting direction and its guide part is inserted into the inner groove, the ultrasonically vibrating broach is sent downward to cut both sides of the inner groove. Finishing the surface with the cutting edge part,
An ultrasonic vibration broaching method characterized in that the broach is removed from the workpiece by being pulled downward as it is.