JPS6316940A - Tool feed gear of machine tool - Google Patents

Abstract

PURPOSE:To enable a machine to stop in case of emergency by causing two intermediate gears to slip with each other when the rotation phase shift between a feed gear and a main spindle driven gear dies out and providing an over load detecting mechanism worked thereby. CONSTITUTION:When a cutting edge 38 is broken, the feeding force against a tool slide 36 is increased more than the feeding force caused by the rotation phase shift between a main spindle drive gear 17 and a feed gear 22 for locking the two gears with each other and integrally rotating. And this causes a first intermediate gear 27 and a second intermediate gear 28 engaging with the main spindle drive gear 17 and the feed gear 22 respectively to slip in relation to each other for starting the second intermediate gear 28 rotating for an inter mediate shaft 26. As a result, a switch 35 is turned ON and an ON signal is transmitted to the control circuit of a machine tool for stopping the machine tool incase of emergency. A feed mechanism can be prevented thereby from being deformed due to overloaded feeding.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a tool feeding device for a machine I machine, and in particular, when the feed of a cutter relative to a workpiece exceeds Ll -1; This article relates to a feeding device that is designed to stop.

[Conventional technology]

2. Description of the Related Art Various types of machine tools for cutting shaft objects, such as crank pins of crankshafts, are known, as seen in Japanese Patent Publication No. 45726/1983 and Japanese Patent Application Laid-open No. 80092/1983.

Among these, machine tools such as pin turning lathes fix and hold both ends of the shaft on a psychological table, rotate the tool head around the outer circumference of the shaft, and feed the tool post to cut the shaft into a predetermined dimension. It is something to do.

GJ is a machine tool for machining shaft objects that fixes the workpiece and rotates the tool.The GJ uses a tool head with a built-in blade feed mechanism to rotate at high speed around the shaft object, thereby increasing the cutting efficiency of shaft objects, such as crankbins of crankshafts. In order to improve this, it is desirable to simplify and reduce the weight of the blade feed mechanism incorporated into the rotating tool head.

Therefore, the applicant of the present application has proposed a machine tool of the JIII type with a workpiece fixing tool that satisfies the demands of the 1980s.
No. 2724 has already been released on the market. In this case, the main shaft drive gear and the feed gear with a smaller number of teeth are coaxially combined, and by rotating both gears through the same gear train, a rotational phase shift is created between the two gears. Utilizing this rotational phase shift motion, a force J formed on the feed gear, a groove, and a cam follower that engages with the groove infeet the blade feed stand installed on the main shaft drive gear.

rProblems that the invention attempts to solve] -1- In a tool feeding device like the one described above, the cutting blade wears out.

When folding tf1 etc. occurs, the cutting speed decreases, the cutting force increases significantly, and the cutting feed becomes overloaded, but since there is no detection means for this, the workpiece is deformed in the radial direction. In addition to being damaged, there were also surfaces that could destroy tool feeders, etc.

[Purpose of the invention]

The present invention was developed in order to solve the above problems, and it ensures the safety of the machine tool even if the cutting blade is abraded, broken, etc. and the cutting feed becomes over-low. It is an object of the present invention to provide a tool feeding device for a machine tool that prevents deformation and destruction of workpieces, feeding tables, etc.

[Means for solving problems]

A tool feeding device for a machine tool according to the present invention includes a hollow main shaft rotatably provided in a processing unit main body, a main shaft driving gear mounted concentrically and integrally with the hollow main shaft, and a main shaft driving gear arranged opposite to the main shaft driving gear. A feed gear that is attached to the hollow main shaft so as to be relatively rotatable and has a different number of teeth from the main shaft drive gear, a motor that rotationally drives the main shaft drive gear and the feed gear, and a motor that rotates the rotation of the motor to the main shaft drive gear. and the feed gear respectively, and is installed on the intermediate gear coaxially with the same number of teeth and the main shaft drive gear so as to be movable in the radial direction thereof, and protrudes toward the outer periphery of the workpiece shaft. a tool feed base having a cutting blade; the feed gear has a ring-shaped infeed cam groove in which a cam follower attached to the tool feed base is press-engaged;
The cutting resistance becomes larger than the feed force due to the rotational phase shift between the main shaft drive gear and the feed gear, and the rotational phase shift between the two gears disappears. It is equipped with a load detection mechanism.

[Action of the invention]

In the present invention, when the main shaft drive gear and the feed gear rotate, a rotational phase shift occurs between the two gears, and as a result, the cam follower traces the cam l seedling, thereby infeeding the tool carriage. When the cutting feed becomes overloaded due to wear or breakage of the cutting blade, the rotational phase shift between the main shaft drive gear and the feed gear disappears, and as a result, the rotation occurs between the intermediate gears meshing with the main shaft drive gear and the feed gear, respectively. A deviation will occur, and by detecting this rotational deviation with the overlow 1' detection mechanism, an emergency stop command is issued and the machine tool is brought into an emergency stop 1-.

Therefore, the cutting edge due to overload of cutting feed.

Destruction and deformation of the feed mechanism, workpiece, etc. can be prevented.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

1, 2 and 3 are plan views of a crank pin cutting machine tool equipped with a tool feeding device according to the present invention, respectively;
2 is a front view and a cross-sectional view taken along line m-m in FIG. 1, and FIGS.
The details of the cycle end detection mechanism and the over 11-1' detection mechanism are shown in (2).

In FIGS. 1 to 3, reference numeral 1 denotes a beso l', and its ten faces have four parallel stripes spaced apart at predetermined intervals in the front-rear direction. Second. Third. Fourth guide surfaces 2a, '1J2c, and 2d are formed along the longitudinal direction of the head 1. 3 is a first guide surface 2a located at one end of the head 1 in the downward direction;
The third guide surface located on the rear side of the second guide surface 21) adjacent to this
A first psychological table 4 is installed so as to be movable in the longitudinal direction of the Bent River astride the - side of the guide surface 2C, and 4 is located at the other longitudinal end of the spatula F1 ( A second psychological table is installed so as to be movable in the longitudinal direction of the head 1, straddling the fourth guiding surface 2d on the rear side of the third guiding surface 2C. Chucks 6.7 for gripping a shaft object, for example, the journal portions 5a at both ends of a crankshaft 50 are provided aligned on the same axis, and inside each psychological table 3, 4, each chuck 6.7 is operated. An index mechanism (
(not shown since both are known techniques) are installed. 8 is located on the side closer to the first tailstock 3 between the respective psychological supports 3 and 4, and is located on the second side of the head 1. 4th guide surface 2
A saddle 9 is a spatula ['
A ball screw 10 rotated by the servo motor 9 is screwed into a pole nut 11 provided on the saddle 8, and by driving the servo motor 9, the saddle 8 is rotated on the crankshaft 5. It can be moved in the axial direction. Reference numeral 12 denotes a machining unit installed movably in the direction perpendicular to the moving direction of the saddle 8''. It is something that will be done.

As shown in FIGS. 4 and 5, the T unit 12 includes a hollow main shaft 15 that passes through the unit main body 14 in the same direction as the moving direction of the saddle 8. It is rotatably supported within the unit main body 14 by spherical bearings 16a and 16b, and a donut plate-shaped main shaft drive gear 17 is concentrically and integrally fixed to the front end of the unit main body 14 with bolts 18, and furthermore, the rear end Bearing presser 1
9 are fixed together with bolts 20. Also,
A ring-shaped feed gear 22 is fitted on the outer periphery of the collar 21 that fits on the outer periphery of the front end of the hollow main shaft 15 so as to be rotatable relative to the hollow main shaft 15. , there are no more than 1 to 1000 births (has the number h).

Reference numeral 23 denotes a drive shaft rotatably supported by the unit body 14, one end of which has a binion gear 24 fixed thereto, and the other end of which is coupled to a rotating shaft 25a of a servo motor 25 fixed to the rear surface of the unit body 14 (coupling 251). connected by. 26 is the drive shaft 23 and the hollow main shaft 1
5, the hollow intermediate shaft is rotatably supported by the unit body 14, and one end thereof has the above-mentioned pinion gear 24.
and the first intermediate gear 2 that meshes with the main shaft drive FJ + gear 17
7 is fixed, and furthermore, a second intermediate gear 28 which has the same number of teeth as the first intermediate gear 27 and meshes with the feed gear 22 is slotted.

1-' pin 29. -1- The slide pin 29 passes through the intermediate shaft 26 in a slidable manner in the diametrical direction, and its one end engages with a recess 28a formed on the inner periphery of the second intermediate gear 2, as shown in FIG. By doing so, the second intermediate gear 28 is coupled to the intermediate shaft 26. Also,
The slide pin 29 has an inclined surface 29a, and this extension 8
The pressing pin 30 that engages with the first surface 29a is located on the intermediate shaft 26
It is slidably inserted inside along the L downward direction.

One end of the operating port 31 inserted into the intermediate shaft 26 is connected to the suppression pin 30, and &f:i is a low H circumference adjusting screw screwed into the other end L of the intermediate shaft 26. 32 to stomach ii! + and protrudes outside the intermediate shaft 26,
Between the nut 33 located inside the intermediate shaft 26 and screwed onto the operating rod 31 and the row 1 adjustment screw 32 (J compression spring 34
is interposed therebetween, and by applying a pressing force to the pressing pin 30 toward the slide l' pin 29 side by the spring 34, the tip of the sliding pin 29 is pressed into engagement with the recess 28a of the intermediate gear 28. .

When the feed gear 22 overrots and there is no rotational phase shift between it and the main shaft drive gear 17 and they are rotated together, the second intermediate gear 28 is rotated relative to the intermediate shaft 26 and the slide pin 29 is rotated. is pushed inward, the movement is transmitted to the operating rod 31, and a switch 35 installed opposite the outward protrusion α11.1 of the operating rod 31 is operated. That is, the intermediate gear 28. Slide pin 29. Press pin 30. Operation Roso F31. The spring 34 and switch 35 constitute an O-Hello F detection mechanism when the feed becomes O-Hello I, and when the switch 35 is operated, an emergency stop 1 command is issued to the machine tool. There is.

On the other hand, on the front wall of the spindle drive wheel 17, a tool feed stand 3 is provided with a hole 36a for inserting the crankshaft in the center.
6 is a pair of parallel retainers 3 removably fixed to the front wall with bolts or the like, as shown in FIGS. 4 and 5.
7a and 37b so as to be slidable in the diametrical direction of the C main drive gear 17, and the central hole 36 shown in -
i:1 on the inner wall of a, and the outline of the shaft such as a crank pin.
A cutting blade 38 for cutting is provided to protrude inward, and a bracket 40 for supporting the roller shaft 39 is disposed perpendicularly through one end side of the tool feeder 36, and this bracket 40 has a tapered ring 41 and by Holt 42,
It is integrally fixed to the tool feed stand 36.

Further, the protruding portion of the bracket 40 toward the main shaft drive gear 17 is inserted into a hole 17a bored in the main shaft drive gear 17 that is sufficiently larger than the outer diameter of the bracket 40, and is inserted into a hole 17a that is sufficiently larger than the outer diameter of the bracket 40. A roller type cam follower 44 that engages with a cam groove 43 formed in an annular shape on the contact surface of the 17 main shaft drive gears of the feed gear 22 is mounted on the protruding end toward the gear 22 side.

-1- The cam groove 43, as shown in the exploded view in FIG.
1' portion 43b, dwell lead portion 43C1, quick return portion 43d, and zero feed portion 43e, each cycle has n (integer) cam surfaces. 43, which are equally divided during one rotation. In addition, in order to press the force roller 44 onto each lead portion of the cam groove 43 to eliminate backlash, the tool feed stand 36 is located opposite to the installation position of the cam follower 44.
A compression spring 45 is attached to the inside of the other end, and both ends of the compression spring 45 are connected to the tool feed table 36 and the main shaft drive gear 1, respectively.
It is latched to a stand 46 fixed to 7.

Next, a mechanism for detecting one cycle of crank pin machining by directly utilizing the movement of the tool feed table 36 will be described.

As shown in FIGS. 4 and 5, the one-cycle end point detection mechanism includes four ports 47 disposed on the hollow main shaft 15 at intervals of 90 degrees in the circumferential direction, and each rod 47 A 4 (llil hole 4) is drilled to a desired depth in the L-plane direction from the front surface (main shaft drive gear 17) side of the hollow main shaft 15.
8 in a slidable manner, and each hole 4
8 is biased in the direction of pressure contact with the back surface of the tool feeder 36 by a compression spring 49 inserted in the
An inclined groove 50 is formed on the back surface of the tool feeder 36 to which the protruding tip of the tool feeder 36 comes into pressure contact, and by pressing and engaging the tip of the rod 47 with the inclined groove 50, the movement of the tool feeder 36 is controlled by the hollow of the rod 47. This is converted into an axial movement of the main shaft 15. Further, on the outer periphery of the hollow main shaft 15,
It has a ring 51 that is loosely fitted so as to be slidable in the axial direction, and this ring 51 has a hole 1 formed in the hollow main shaft 15.
5a with a set screw 52 of 1ffiL to each of the above-mentioned rods 4.
It is fixed at 7. Reference numeral 53 denotes a proximity switch that operates by sensing the position of the ring 51, and the switch 53 is arranged on the outer periphery of the hollow main shaft 15 and attached to the support member 54. Further, 55 is a position sensor for stopping the hollow main shaft 15 in a fixed position attached to the support member 54, and the position sensor 55 is operated on the outer peripheral surface of the hollow main shaft 15 facing the position sensor 55. Stop 1 part 56
is fixed.

Next, the operation of this embodiment configured as described in section 1 will be explained.

When cutting the crank pin 5b of the crankshaft 5 by fixing the workpiece and rotating the tool, first move the psychological tables 3 and 4 to the 1° and 3rd guide surfaces 2a and 2C depending on the stiffness of the crankshaft 5.
and second. Fourth guide surface 2b.

2d and fixed at a position that matches the length of the crankshaft 5. Thereafter, the journal portions 5a at both ends of the crankshaft 5 are gripped by the chucks 6.7 of the respective psychological tables 3 and 4. At this time, the indexing mechanism of the chuck 6.7 operates to determine the phase of the rotational direction of the crankshaft 5.
The crank pin 5b of IP and #3P is horizontal to the core of the journal portion 5a! placed in the room.

Then, by driving the servo motor 9 and rotating the ball screw 10, the shaft 8 is moved in the six directions of arrows in FIG. 1, and the cutting blade 38 is opposed to, for example, the #4P crank pin 5b. Position it accordingly. Once the positioning of the cutting blade 38 to the #4P crank pin 5b has been completed, the hydraulic cylinder 13 is activated and the processing unit is activated.
2 is moved to a position where the axis of the hollow main shaft 15 coincides with the center of the crank pins 5b of #IP and #4P, and the machine tool is shifted to the crank pin cutting mode.

When the servo motor 25 for q+ cutting is activated by the cutting mode setting of the machine tool, its rotation is transmitted to the main shaft drive gear 17 and feed gear 22 via the drive shaft 23, pinion gear 24, and intermediate gears 27 and 28. Ru. Accordingly, the main shaft drive gear 17 is rotated together with the hollow main shaft 15, and the feed gear 22 is rotated around the collar 21.

Here, if the number lJ1'i of the main shaft drive gear 17 is M, the number of teeth of the feed gear 22 is M-1. Therefore, when the main shaft drive gear 17 rotates N times, the feed gear 22 rotates N+1 times. That is, a phase shift corresponding to one rotation occurs between the main shaft drive gear 17 and the feed gear 22, and the tool feed carriage 36 is in-feeded by the shifted rotation between the two and the cut and groove 43.

That is, due to the relative rotational deviation between both gears 17 and 22,
Cam follower 4 that is constantly pressed by compression spring 45
4 engages the rapid advance lead portion 43a from the zero-feed portion 43e in the cam groove 43 in FIG.
a, it is rapidly advanced in the direction approaching the crank pin 5b (94P). Then, when the cam follower 44 moves to the lead portion 43b, the tool feed stand 36 moves to the infee V
Enters a small cutting feed and crank pin 5b (#4P
) is cut by the cutting blade 38. In the next dwell area 43C, the outer diameter of the crank pin 5b is finished cut to a predetermined size.

Then, when the cam follower 44 passes through the F L phase lead part 43C and comes to engage with the fast return lead part 43d, the tool feed base 36 including the cutting blade 38 is fast returned, and the cutting blade 38 is cut. Completed crank pin 5b (#4P
) to rapidly retreat in the direction away from the vehicle.

In the speed pattern of the servo motor 25 during the second cutting cycle, the servo motor 25 is rotated at a constant speed (2) at a high speed in the range of the relative deviation angle θ1 to θ2 between the gears 17 and 22.

On the other hand, when the cutting feed is applied to the tool feeder 36 and the tool feeder 36 moves in the direction of arrow B in FIG.
4, and the rings 51 move in the same direction at the same time.

After the crank pin 5b has been cut to a fixed size, when the tool feed bar 36 starts to be moved to a quick return mode, the ring 51 is moved in the direction opposite to the arrow C in conjunction with this movement.
1 count.

When the proximity switch 53 detects this, the proximity switch 53
A signal is sent from the servo motor 25 by applying this signal to the control circuit (not shown) of the servo motor 25.
The rotational speed of the servo motor 25 is brought to a predetermined low speed v1 as shown in FIG.
．． When the relative deviation rotational speed of 22 reaches 360°/mouth, that is, the angle θ3 at which one cycle of the movement of the cutting blade 3B ends,
The position sensor 55 senses the fixed position stop part) As2 and applies the signal to the control circuit of the servo motor 25, thereby applying a sudden brake to the servo motor 25 to stop the hollow main shaft 1.
5 to the fixed position +1-.

The stopping position at this time is a position having a rotational phase difference of 180° from the counterweight of the crankshaft 5, and the positional relationship between the cutting blade 3B and the crank pin 5b (廿4P) as shown in the fourth figure. Become. This is done because if the stop h position described in -1- deviates significantly, the cutting blade 38 and the crankshaft 5 will interfere when moving the machining unit I.12 in the axial direction of the crankshaft 5. It is.

In addition, even if the stopping position of the hollow main shaft I5 is normal, the positioning of the tool unit 12 in the longitudinal direction of the crankshaft may be incorrect, or the (i'!) position indexing of the crankshaft 5 in the rotational direction may be defective. Starting the servo motor 25 in consideration of 4
The hollow main shaft 15 is rotated once at a low speed and in a torque-limited state to confirm whether or not the cutting blade 38 and the crankshaft 5 are in a normal positional relationship. Control in this case is performed by a timer not shown, and corresponds to the range θ0 to θ1 in FIG. 7 ([l).

If the crankshaft 5 and the cutting blade 38 interfere with each other during one rotation of the hollow main shaft 15, the hollow main shaft 15
Since the rotation of the hollow spindle 15 stops, even if the time elapses longer than the set timer, the hollow spindle 15 will make one revolution. Therefore, such abnormalities can be easily discovered, and it is also possible to stop the cutting cycle of the machine tool. become.

On the other hand, during the cutting cycle of the crank bin 5b, the cutting blade 3
8 wears out and the cutting resistance increases significantly, or the cutting blade 38 breaks 10, causing the feed force to the tool feed base 36 to increase due to the rotational phase shift between the main shaft drive gear 17 and the feed gear 22. If it becomes overloaded,
Camfo 1 core 44 and cam groove 43 are locked! Suddenly, the main shaft drive gear I7 and the feed gear 22 become integrated, and they are rotated together without any rotational phase shift. For this reason, the first intermediate gear 27 and the second intermediate gear mesh with the main shaft drive gear 17 and the feed gear 22 separately.
A rotational deviation occurs between the intermediate gear 28 and the intermediate gear 28. That is, the second
Since the intermediate gear 28 of starts rotating with respect to the intermediate shaft 26,
The slide 1 pin 29, which had been recessed into the four parts 28a of the second intermediate gear 28, moves in the direction of the arrow in FIG. 6 against the spring 34, and the pressing pin 30 engages with its inclined surface 29a.
Then, the operating rod 31 connected thereto is slid in the direction of arrow E in FIG. 4, and the switch 35 is turned on. When this switch 35 is turned on, the on signal is supplied to a control circuit (not shown) of the machine tool, and the machine tool is brought to an emergency stop. This makes it possible to prevent deformation or destruction of the feeding mechanism etc. due to the feeding being OH LOW 1-.

Note that the overload on the feed gear 22 can be adjusted by adjusting the spring pressure of the spring 34 using the adjustment screw 32.

Further, the tool feeding device according to the present invention is not limited to machining the crankshaft of the rank shaft as in the above embodiment, but can of course also be used for machining cylindrical cams and other shaft objects.

[Effects of the Invention] As described above, according to the present invention, the main shaft drive gear and the feed gear are rotationally driven via separate intermediate gears having the same number of teeth and provided on the same axis, and the main shaft drive gear and the main shaft drive gear When the feed force 3L due to the rotational phase deviation between the gears increases and the cutting resistance increases and the rotational phase deviation between the Oka gears disappears, a rotational deviation occurs between the two intermediate gears, and the overrot operates due to this rotational deviation. A detection mechanism is installed to prevent excessive cutting feed.
-1'' can be detected and the machine tool can be brought to an emergency stop, so even if the cutting feed reaches 1' due to wear or breakage of the cutting blade, the safety of the machine tool can be ensured, and the workpiece and feed mechanism It is possible to prevent deformation and destruction such as the like.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a crankshaft cutting machine tool equipped with a tool feeding device according to the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a sectional view taken along line I■-■ in FIG. FIG. 4 is a cross-sectional view of an example of the tool feeding device according to the present invention, and FIG.
A side view taken along the line V-V in the figure, Figure 6 [J Figure 4 Vl-
A sectional view taken along the Vl line, FIG.
is a speed pattern diagram of a main shaft zarpo motor corresponding to a cam groove for inserting a cutter. 12...Processing, :l-sol-114...Uniso 1~
Main body, 15... hollow main shaft, 17... main shaft drive gear,
21... Collar, 22... Feed gear, 23... Drive shaft, 24... Pinion gear, 25... Servo motor, 26... Intermediate shaft, 27° 28... Intermediate gear, 2 1...slide 1' pin, 30...press in, 31...
・Operation Roso F, 34...Spring, 35...Switch,
36... Tool feed stand, 38... Cutting blade, 43...
Infeed force 1, groove, 44...cam follower, 4
7...1 cycle detection loft, 50...slanted groove,
51...Ring, 53...Proximity switch.

Claims (2)

[Claims] (1) A hollow main shaft rotatably provided on the main body of the processing unit, a main shaft drive gear mounted concentrically and integrally with this hollow main shaft, and a main shaft drive gear mounted opposite to this main shaft drive gear to be relatively rotatable on the hollow main shaft. , and a feed gear having a different number of teeth from the main shaft drive gear, a motor for rotationally driving the main shaft drive gear and the feed gear, and a motor that transmits the rotation of the motor to the main shaft drive gear and the feed gear separately, and a coaxial drive gear. an intermediate gear having the same number of teeth, and a tool feed stand installed on the main shaft driving gear so as to be movable in the radial direction thereof and having a cutting blade protruding toward the outer periphery of the shaft to be machined; The feed gear is formed with a ring-shaped cam groove for infeed, which is pressed into engagement with the cam follower attached to the tool feed stand, and the cutting resistance is reduced due to the feed force caused by the rotational phase shift between the main shaft drive gear and the feed gear. A tool feeding device for a machine tool, characterized in that the rotational phase shift between the two intermediate gears is eliminated, and an overload detection mechanism is provided that operates based on the rotational shift generated between the two intermediate gears. (2) The overload detection mechanism includes a slide pin that engages and disengages an intermediate gear meshing with the feed gear from the shaft of another intermediate gear, and a spring that biases the slide pin in a direction to engage the intermediate gear; Turns on and off in conjunction with the movement of the slide pin.
A tool feeding device for a machine tool according to claim 1, further comprising a switch that is turned off.