JPH0283130A - Composite machining dedicated equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is applicable to multiple machining processes that require precision in the coaxiality of the seat surface of a valve hole and the center of a valve guide hole, etc., for example, in the machining of engine cylinder heads. This relates to a dedicated machine for multi-processing in one process.

(Conventional Technique VF1) In general, this type of dedicated machine is equipped with a tool spindle on the saddle of the feed unit in order to perform, for example, polling the seat surface of the valve hole in the cylinder head and gun reaming the valve guide hole in two steps. is rotatably supported, and a first tool feed shaft for polling and a second tool feed shaft for gun reaming are concentrically arranged inside this tool spindle, integrally in the rotational direction and slidable in the axial direction. It is set up and configured.

First, the feed unit is moved to the machining start end, and from this point, the plunge cut tool provided on the tool spindle is rotated and advanced by the machining feed to make a plunge cut on the end face of the valve hole.After this, the feed unit is moved to the desired position. Relieve the plunge cut tool by retracting it a certain amount, and while rotating and advancing the first tool feed shaft, poll the seat surface of the valve hole with a polling tip or the like.
Next, while rotating and advancing the second tool feed shaft, gun reaming of the valve guide hole is performed using a gun reamer.

(Problem to be solved by the invention) In this type of machining, high centering accuracy is required between the seat surface of the valve hole and the valve guide hole, and extremely precise finishing accuracy of the seat surface is also required. This is what is required. To do this, it is necessary to ensure the accuracy of the relief amount to prevent tool interference with the machined surface, to position the machining start position of the next stage sheet surface using this relief feed, and to use the first tool feed axis for polling machining, which is a minute feed. The accuracy of the feed amount is important.

In addition, in conventional devices, when the transmission belt that transmits rotation to the tool spindle becomes worn or damaged and requires repair or replacement, it is very time-consuming to remove and install the belt.

For example, in FIG. 11, first, the first and second tool feed shafts a and b are returned to the retracting limit position, and the cover e tightening the fastening body d at the joint between the second tool feed shaft and the shaft holder C. Measure the distance (S dimension) between and the reference surface on the feed axis side.

Next, remove the hose joint g, remove the bracket h, and then remove the bolt 1f of the cover e! :11 Loosen the fastening body d fixing the feed shaft for the first time. Next, put a spanner on it
Unthread the threaded end 8 of the feed shaft from the tool holder H by applying a wrench and turning the tool holder H at the tip several times. Pull it out about 100 mm and pull the screw end B backward from the position of the coupling as shown in FIG. 7 B°.

A sleeve 11 serves as a joint for the first tool feed shaft a.
! :Remove. For this, loosen the bolt m and
, then loosen bolt 0 and remove collar p, move sleeve 1 forward to remove coupling k from bearing holder q, and then move sleeve l back again to remove it from feed shaft a.

The belt t was moved in and out in the space r between the feed shaft a and the bearing holder q.

In addition, after replacing the belt t from this space r, it is reassembled in the reverse order as described above, but at that time, tighten the bolt 1 accurately so that the S dimension before disassembly is measured. Adjustment work is required.

In this way, in the past, the work when replacing the belt was very complicated and time-consuming, and the work area for disassembly spanned the entire length of the processing equipment, resulting in poor workability.Moreover, it was difficult to measure the S dimension before disassembly and to reassemble the belt. This required adjustment of the S dimension at the time, and was a very delicate task.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to enable highly accurate minute feed of the tool feed axis for machining that requires high precision, improve machining accuracy, and reduce the space for replacing the rotating power transmission belt. The purpose is to easily form the structure by simply removing the joint members of each shaft near the rotating portion, and to simplify the work of replacing the transmission belt.

(Means for Solving the Problems) The present invention provides a feed unit and a first tool concentric with the tool spindle.
Numerical control is used to control the feed of the tool feed axis and the second tool feed axis to improve the precision of the machining feed and relief feed of each axis, and each feed axis is numerically controlled via a differential screw mechanism. This is intended to enable highly accurate micro-feeding and improve machining accuracy.

Furthermore, the present invention forms a joint part for each feed shaft near the hanging part of the belt for rotational transmission, and by removing the joint member of this part from each feed shaft, the belt can be replaced there. The space for belt replacement can be created by simply disassembling the joint.
Belt replacement is extremely easy and safe, reducing work time, and does not require precise work processes such as measuring the dimensions of the connection part with the shaft feed drive, and does not require readjustment during assembly. First, it is extremely easy to repair.

That is, the present invention supports a tool spindle rotated by a rotary drive motor on the saddle of a feed unit, and has a first tool feed shaft and a second tool feed shaft inside the tool spindle that are rotated together with the tool spindle. are provided concentrically so as to be freely movable in the axial direction, and the feed unit, the first tool feed axis, and the second tool feed axis are each fed and driven by numerical control, and the first tool feed axis or the second tool feed axis is is configured to be numerically controlled via a differential screw mechanism.

In addition, the first tool feed shaft and the second
Joint parts are formed on each of the tool feed shafts, and by removing the joint members forming the joint parts, a space for replacing the power transmission belt can be created.

(Embodiment) Next, a specific embodiment of the present invention will be described with reference to FIGS. 1 to 6.

Fig. 1 is a side view of the dedicated multi-tasking machine of the present invention, Fig. 2 is a sectional view of the processing tip, Fig. 3 is an explanatory diagram showing the positional relationship between the processed surface of the seat ring and each tool, and Fig. 4. 5 is a sectional view of the shaft feeding drive portion, FIG. 5 is a sectional view of the joint portion, and FIG. 6 is a sectional view showing a state in which a space for replacing the belt is formed.

First, in FIG. 1, the multi-purpose processing machine 1 has a bed 2
A feed unit 3 is provided above, and a tool spindle 6 rotated by a rotary drive unit 5 is mounted on the saddle 4 of the feed unit 3.
f! : Rotatably supported, and a first tool feed shaft 7 and a second tool feed shaft 8 are provided concentrically inside the tool spindle 6, respectively.
are fitted integrally in the rotational direction and slidably in the axial direction, respectively, and a first feed drive section 9 that feeds and drives the first tool feed shaft 7 and a second feed drive section that feeds and drives the second tool feed shaft 8. A drive section 10 is provided. And cylinder head W
This allows finishing of multiple parts of the valve hole and valve guide hole to be performed in one process.

The feed unit 3 feeds the saddle 4 forward and backward toward the clamped workpiece W via the feed motor M and a feed screw mechanism (not shown) under numerical control. On the saddle 4, there is a headstock 13 and a plurality of support stands 1.
4.15.16 is installed. The headstock 13 has the tool spindle 6 fixed in the axial direction and the bearing 1
7.18, and the support base 14 is rotatably supported by a variable speed rotary drive motor 1 which is a drive source of the rotary drive unit 5.
9ti0: supported, and the support stands 15 and 16 support the first feed remoter 20 of the first feed drive unit 9 and the second feed remoter 21 of the second feed drive unit 10, respectively. These feed motors 20, 21 are also numerically controlled.

Next, in FIG. 2, a substantially conical tool holder 22 is fixed to the tip of the tool spindle 6 with a bolt 23. As shown in FIG. Plunge cut tools 24 and 25 are attached to the tip side of this holder 22, and a mounting portion 27 for a first tool 26 for traverse cut is formed on the other side.

A slide piece 29 is slidably supported on this mounting portion 27 on a sliding guide surface 28 inclined at approximately 45 degrees with respect to the spindle axis direction, and the first tool 26 is fixed to the tip of this slide piece 29. ing. Further, a through hole 30 opening in the guide surface 28 is formed, and a solidly crushed engager 31 integrated with the first tool feed shaft 7 is inserted into the through hole 30 so as to be movable in the axial direction. The tip of the engaging element 31 engages with the slide piece 29, converting the axial movement of the first tool feed shaft 7 into an inclined movement of the slide piece 29 along the guide surface 28. In addition, at the retraction limit of the first tool feed shaft 7, the cutting edge of the first tool 26 is set at a position that does not protrude beyond the cutting edges of the plunge cutting tools 24, 25.

Further, a second tool 32 for gun reaming is coaxially mounted on the tip of the second tool feed shaft 8.

That is, as shown in FIG. 3, the plunge cutting tool 24.25 is sent in the axial direction by the feeding unit 3 together with the movement of the saddle 4, and processes the two end surfaces 33.34 of the seat ring 12. .

Further, the first tool 26 mounted on the slide piece 29 is traverse-fed by the movement of the first tool feed shaft 7 to process the seat surface 35 of the seat ring 12. Further, the second tool 32 is fed in the axial direction together with the movement of the second tool feed shaft 8 to process the valve guide hole 11. In this way, three types of processing can be performed with the same device.

Next, referring to FIG. 4, the configuration of each feed drive section 9.10 of the first tool feed shaft 7 and the second tool feed shaft 8 will be explained.

The first tool feed shaft 7 also has a threaded portion 7 on its tip side shaft member.
Since they are integrally connected via a, the integrally connected shaft portion along the entire length of the shaft will be generically referred to as the first tool feed shaft 7, including the shaft member on the distal end side. Also,
The second tool feed shaft 8 also has a shaft member on its tip side and a threaded portion 8a.
Therefore, the integrally connected portion of the entire length of the shaft, including the shaft member on the distal end side, will be generically referred to as the second tool feed shaft 8.

A hollow shaft 37 is connected to the first tool feed shaft 7 via a universal joint 36.
The inner ring of the ball bearing 38 is held at the outer periphery of the hollow shaft 37, and the outer ring is held by a bearing case 39 on the outer periphery. One end portion of a vertical first reciprocating plate 40 is integrally connected to this bearing case 39 . The first reciprocating plate 40 is rotatably fitted into an annular recess 37a formed on the outer periphery of the hollow shaft 37. Further, the other end of the first reciprocating plate 40 is supported by a guide rod 41 parallel to the axial direction.

A cylindrical shaft 43 is connected to the motor shaft 20a of the first feed remoter 20 provided on the support base 15 via a fastening body 61 that is tightened to the cover 42 by bolts 65. The first feed screw 44 is connected to this cylindrical shaft 43.
are integrally connected in the rotational direction and slidably in the axial direction via a spline 45.

This first feed screw 44 has two thread pitches different from each other.
One threaded part 46 is screwed into a first nut 48 fixed to the support base 15, and the other threaded part 47 is threaded into a second nut 48 fixed to the first reciprocating plate 40.
9 and constitutes a differential screw mechanism 50.

That is, with one rotation of the motor 20, the first feed screw 44 itself moves by the lead amount set by one threaded portion 47;
Since the first advancing/retracting plate 40 moves in the opposite direction relative to the feed screw 44 by the amount of lead set by the other threaded portion 46, the lead amount of the difference between the two lead amounts is the actual amount of the first advancing/retracting plate 40. Lead amount. Thereby, minute feed control can be performed very accurately and easily.

On the other hand, the hollow shaft 52 is coupled to the second tool feed shaft 8 via a fastening body 62 which is similarly tightened to the cover 51 by bolts 66. And this hollow shaft 52
The outer periphery of the ball bearing 53 holds the inner ring of the ball bearing 53, and the outer periphery of the bearing case 54 further holds the outer ring. One end portion of a vertical second reciprocating plate 55 is integrally connected to the bearing case 54 . The second reciprocating plate 55 is rotatably fitted into an annular recess 52a formed in the hollow shaft 52.

Further, the other end of the second reciprocating plate 55 is supported by one end of a shaft 56 parallel to the axial direction.

This shaft 56 is slidably inserted into the support base 15, and a vertical connection plate 57 is attached to the other end.

A second feed screw 59 is connected to the motor shaft 21a of the second feed remoter 21 provided on the support stand 16 via a universal joint 58. This universal joint 58 has each shaft 21a, 59
are connected to each other via fasteners 63 and 64 by tightening bolts 67 and 68, respectively. The second feed screw 59 is rotatably supported by the support base 15 and has a threaded portion 59a at its tip m.

This threaded portion 59a is screwed into a nut 60 fixed to the connection plate 57.

Furthermore, a bracket 69 supports a rotary joint 70 at the rear end of the second tool feed shaft 8 . And this bracket 6
A hose joint 71 is attached to 9, and a cutting agent is supplied from a supply section (not shown) to a cutting agent supply path 72 formed inside the second tool feed shaft 8 and opened at the tip of the second tool 32.

Next, at the rear left of the headstock 13, a pulley 73 is integrally coupled to the tool spindle 6 via a fastening body 74 formed by tightening a bolt 75. A transmission belt 76 (herein referred to as a belt) for transmitting rotation from the rotary drive motor 19 is suspended on this pulley 73.

A joint portion 77 for each tool feed shaft 7.8 is provided between the pulley 73 and the universal joint 86 and near the pulley 73. This joint part 77 is the fifth
As shown in the figure, the first tool feed shaft 7.
Wari color 78 that engages in the rotation direction is connected to 7 darkness,
Fit the holder 80 onto the outer periphery of these and tighten the tightening screw 8.
1, the first tool feed shaft 7.7 is integrally connected.

Further, inside the second tool feed shaft 8.8, connecting shafts 82.83 are screwed onto the respective shafts 8.8 as joint members and are connected to each other by tightening a key 84 and a bolt 85. , the second tool feed shaft 8.8 is integrally coupled.

(Effect of Example) Next, the machining operation will be explained.

By driving the rotary drive motor 19, the tool main shaft 6 and each tool feed shaft 7.8 are rotated integrally via the belt 76. All axis feeding is done by numerical control. First,
The saddle 4 is rapidly fed toward the workpiece W to the machining start position, and machining feed starts from this position.

First, the seat ring 12 is plunge cut. By further advancing the saddle 4, the plunge cutting tool 24.25 provided on the tool spindle 6 is advanced, and both end surfaces 33.34 of the seat ring 12 of the workpiece W are cut simultaneously. After this, the saddle 4 is moved back by a predetermined amount, and the tool 24.
25 from both end faces 33 and 34. In this position, the cutting edge of the first tool 26 is positioned exactly on the extension line of the finished surface to the seat surface 35, as shown by the two-dot chain line 26' in FIG. is set to .

Second, the seat surface 35 is traversed from this position. In FIG. 4, the first feed screw 44 is rotated via the shafts 20a and 43 by the drive of the first motor 20.

At the same time, the first feed screw 44 advances by a predetermined lead amount (L) with respect to the first nut 48 on the fixed side. On the other hand, the first reciprocating plate 40 is connected to the second feed screw 44.
Since it is retracted by a predetermined lead amount <t> via the nut 49, the first reciprocating plate 40 is actually moved minutely by the lead difference (L-1,') by the differential screw mechanism 50.

The first advance/retreat plate 40 is advanced from the bearing case 39 via the hollow shaft 37. As a result, the engager 31 fixed to the tip of the first tool feed shaft 7 slides the slide piece 29 toward the center along the slide guide surface 28 as shown by the two-dot chain line in FIG. As a result, the first tool 2 provided at the tip of this slide piece 29
6 in the direction of the above-mentioned extension line to the position shown by the three-point chain $126' in FIG. 3, the sheet surface 35 of the workpiece W is cut. This cutting ends at the position where the first tool 26 passes the sheet surface 35.

Third, the valve guide hole 11 is subjected to gun reaming.

In FIG. 4, the second feed screw 59 is rotated by driving the second motor 21. In FIG. At the same time, the connecting plate 57 is advanced through the nut 60, and the second reciprocating plate 55 is advanced through the shaft 56 integrated therewith.

This second advancing/retracting plate 55 advances the second tool feed shaft 8 from the bear link case 54 via the hollow shaft 52 .

As a result, the 21st tool 32 at the tip is moved forward as shown by the two-dot chain line in FIG. 2, and the valve guide hole 11 of the workpiece W is cut.

All machining is now completed, the second feed remoter 21 is reversely rotated to return the second tool feed shaft 8 in rapid traverse, and then the saddle 4
is returned in rapid traverse, and further, the first motor 20 is reversely rotated to return the first tool feed shaft 7 in rapid traverse. When the tool returns to the retreat limit (original position) in this manner, the machining cycle ends.

On the other hand, when repairing or replacing the transmission belt 76 that transmits rotation to the tool spindle 6, a belt replacement space is formed at the joint portion 77.

That is, both the first tool feed shaft 7 and the second tool feed shaft 8 are positioned at the retraction limit (original position), and the first tool feed shaft 7 is first uncoupled from the coupled state shown in FIG. teeth,
First, loosen the bolt 81 and move the holder 80e rearward as shown in FIG.

Then, remove Warikara-78.

Next, the second tool feed shaft 8 is disconnected. To do this, first loosen the bolt 85, disconnect the coupling shafts 82 and 83, and push the front coupling shaft 82 forward.

Thereby, a space 86 for belt replacement is formed between the connecting shaft 82 and the connecting shaft 83.

The transmission belt 76 is removed from the pulley 73 and taken out from the space 86.

After repair or after installing a new transmission belt 76, reassemble it in the reverse order as described above to return to the state before disassembly. At this time,
The first tool feed shaft 7 is connected to the rear hollow shaft 37 by the universal joint 36, so when reassembling it, there is some distance between it and the first tool feed shaft 7 in the front with the wari collar 78 in between. Even if misalignment occurs, it can be absorbed by this universal joint 36 portion.

In this way, the belt replacement space 86 can be formed without touching the connecting portion of each tool feed shaft 7.8 to the feed drive section, so there is no fear of feed errors due to reassembly, and the belt replacement space 86 can be formed without touching the connecting portion of each tool feed shaft 7. The belt can be easily replaced by simply disassembling the joint part 77 at a position near the suspension part.

In the above embodiment, the transmission belt 76 for rotation transmission is
Although a belt is used, the present invention is not limited to this, and a chain belt, a timing belt, etc. may also be used, and in this case, a driven shaft such as a sprocket that engages with the belt is provided on the tool main shaft 6 side.

(Fifth Modification) Furthermore, the structure of the joint portion 77 is not limited to the above-mentioned embodiment, but may also be structured as shown in FIGS. 7 to 10, for example.

Fig. 7 is a sectional view showing the joint part, Fig. 8 is a sectional view taken along the line X-X, and Fig. 9 is a sectional view of the joint part when the first and second tool feed shafts 7. A view from the Y direction of the figure,
FIG. 10 is a diagram showing a state in which a space for belt replacement has been formed from the state shown in FIG. 9.

As shown in FIG. 7, between the second tool feed shafts 8.8, connecting shafts 87.88 are screwed onto the respective shafts 8.8 as joint members, and are connected to each other by tightening bolts 89.89. The second tool feed shaft 8.8 is connected integrally with the second tool feed shaft 8.8. In addition, between the front shaft 8 and the connecting shaft 87,
A collar 90 is interposed to adjust the assembly phase between the two.

A pair of bolt fastening parts 87a, 87a are integrally formed on the connecting shaft 87 and project in a straight line direction passing through the center of the shaft, and bolt insertion holes 91, 91 are formed in each of them. Opposed to this, a pair of bolt fastening parts 88a5881L are also integrally formed on the connecting shaft 88 so as to protrude from each other, and screw holes 92 and 92 are formed in each of them. These fastening portions 87a and 88a are then tightened together with the bolts 89 and 89.

Further, as shown in FIG. 9, cylindrical collars 93 are provided at two locations between the first tool feed shafts 7 and 7 as joint members.
Insert 93 and tighten the bolt, for example, one bolt 94.94
By tightening, the first tool feed shaft 7.7 is integrally connected.

The first tool feed shafts 7.7 are each provided with relief holes 95.95 that pass through the center of the shaft in a straight line to both sides. This relief hole 95 is cut out long in the axial direction, and both fastening portions 87a and 88a of the connecting shaft 87, 88 are respectively protruded outward from this relief hole 95, and movement in the axial direction is permitted. has been done.

Although not shown in Fig. 7, the first tool feed shaft 7.7
As shown in FIG. 8, a pair of bolt fastening parts 96 and 96 are integrally formed to protrude in a direction intersecting 9° with the protruding direction of both fastening parts 87a, 87a of the connecting shaft 87. There is. The collar 93. is inserted into each bolt insertion hole 97 and reamer hole 98 formed in the pair of fastening portions 96.96.
Reamer bolts 94 and 94 are tightened through 93.

In this way, each bolt fastening part 87 a s 87 a,
96 and 96 are all exposed to the outside beyond the outer diameter of the shaft, so it is very easy to check the condition of bolt tightening work and tightening of each bolt 89 and 94.

In such a joint structure, when replacing the transmission belt 76, the first and second tool feed shafts 7.8 are positioned at the backward limit as shown in FIG. 4 bolts 89.89.94.9
Loosen all 4 and pull out bolts 94 and 94. As a result, the two collars 93.93 are removed, and a link-shaped space 99 is formed around the entire circumference of the first tool feed shaft 7.7.

By pulling the fastening portions 87a, 87a of the front connecting shaft 87 forward, as shown in FIG.
completely retreats forward from the end face on the space 99 side, thus forming a space 100 for belt replacement here.

In this case, the disassembly order of the joint part 77 is which shaft 7
．． Step 8 may be performed first, and the priority order of the connections after the belt is attached does not matter.

Furthermore, the joint structure is extremely compact, and the outer diameter of the joint portion 77 can be kept to a minimum.

(Effects of the Invention) According to the present invention, the numerical side m is used for each feed drive of the feed unit, the first tool feed axis and the second tool feed axis that are concentric with the tool main axis that is advanced and retreated by the feed unit, Moreover, by numerically controlling each feed axis via a differential screw mechanism, highly accurate microfeeding is possible, so for example, when machining the seat surface of a valve hole, which requires extremely precision, the previous stage Since the relief feed after plunge cutting can be performed accurately, the sheet surface machining start position can be accurately positioned, and if the traverse mechanism is used, the precision of the finished surface of the sheet surface is improved, and the accurate feed increases the machining accuracy. Therefore, it contributes to quality improvement.

In addition, by forming a joint part for each tool feed shaft near the hanging part of the transmission belt for rotation transmission,
By removing this joint member from each tool feed shaft, a space for belt replacement can be easily created there. Moreover, since the space for replacing the belt can be created by simply disassembling the joint, when repairing or replacing the belt, the belt can be installed and removed very easily and safely, reducing work time. There is no need for careful work processes such as measuring the dimensions of the connection part with the shaft feed drive, and there is no need for readjustment during assembly. Since this can be done without touching the connecting part of the shaft to the feed drive unit, there is no fear of feed errors due to reassembly.

[Brief explanation of the drawing]

Fig. 1 is a side view of the dedicated multi-tasking machine of the present invention, Fig. 2 is a sectional view of the processing tip, Fig. 8 is an explanatory diagram showing the positional relationship between the processed surface of the seat ring and each tool, and Fig. 4. 5 is a sectional view of the shaft feed drive part, FIG. 5 is a sectional view of the joint part, FIG. 6 is a sectional view showing a state in which a space for replacing the belt is formed, and FIG. 7 is a sectional view showing a modification of the joint part. Figure 8 is the X
- A sectional view taken along the X arrow; FIG. 9 is a view taken from the Y direction of FIG. 7 when the first and second tool feed shafts are positioned at the retraction limit;
FIG. 10 is a diagram showing a state in which a space for belt replacement has been formed from the state shown in FIG. 9, and FIG. 11 is a sectional view of the conventional device. 1... Multi-purpose processing machine, 3... Feeding unit, 4...
... Saddle, 6... Tool main shaft, 7... First tool feed axis, 8... Second tool feed axis, 11... Valve guide hole, 12... Seat ring, 19... Rotation drive motor, 20... first feed remoter, 21... second feed remoter, 26... first tool, 32... second tool, 35
... Seat surface, 50... Differential screw mechanism, 76...
Transmission belt, 77... Joint part, 78... Wari collar as a coupling member 82.83... Connection shaft as a coupling member, 86... Space, 87.88... Connection shaft as a coupling member , 87a, 88a... bolt fastening section, 8
9... Bolt, 93... Collar as a joint member
100...Space, M...Feed motor, W...Work. Patent applicant Nippei Toyama Co., Ltd. Figure 6 Y Figure Figure

Claims (4)

[Claims] (1) A tool spindle rotated by a rotary drive motor is supported on the saddle of the feed unit, and inside the tool spindle there is a first tool feed shaft and a second tool spindle that rotate together with the tool spindle.
Dedicated to compound machining, characterized in that tool feed axes are provided concentrically and slidably in the axial direction, and the feed unit, the first tool feed axis, and the second tool feed axis are each fed and driven by numerical control. Machine. (2) The multi-tasking dedicated machine according to claim 1, wherein the first tool feed shaft or the second tool feed shaft is fed and driven by a numerically controlled feed motor via a differential screw mechanism. (3) In the dedicated multi-tasking machine according to claim 1, the first tool feed shaft and the second tool feed shaft each have joint portions in the vicinity of the hanging portion of the transmission belt that transmits rotation from the rotary drive motor to the tool main shaft. A dedicated multi-processing machine characterized in that a space for replacing a power transmission belt can be created by forming a joint part and removing a joint member forming the joint part. (4) The joint part is formed so that the bolt fastening part of the joint member of the inner tool feed shaft of the first and second tool feed shafts passes through the outer tool feed shaft and is exposed to the outside. 4. A specialized multi-processing machine according to claim 3.