JPH0243644Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a cutting tool holding device equipped with a cutting oil passage for supplying cutting oil to the cutting edge of the tool.

(Prior Art and its Problems) As shown in FIG. 4, a stopper pin (cutting oil intake portion) 18 is provided in the unit case 17, and the inside of the stopper pin 18 is used as an oil passage for removing cutting oil. That is, the oil hole 32 of the tool 26 communicates with the stopper pin 18 via the oil passage 47 in the rotating shaft 16 and the oil passage 29 in the unit case 17, and the intake port 18a of the pin 18 communicates with the cutting oil supply pump 14.
is connected to. The tool 26 is fitted into the tapered hole of the rotating shaft 16, and the oil hole 32 of the tool 26 is fitted into the taper hole of the rotating shaft 16.
It has reached the cutting edge of No. 6. Devices similar to this are also disclosed in U.S. Pat.

However, in the above-mentioned device, a loss of pressure and flow occurs in the oil passage of the holding device until the cutting oil reaches the cutting edge of the tool 26 from the intake port 18a, and the discharge amount and pressure at the cutting edge portion decreases. The cooling effect decreases.

As a countermeasure against such a pressure drop, a system has been developed in which an intermediate pressure increase pump linked to the rotating shaft is provided in the oil passage in the holding device, as disclosed in Japanese Utility Model Application Laid-Open No. 59-170150. However, simply providing a pump for intermediate pressure boosting leaves the following problems.

Generally, when the material of the cutting edge is constant, the thicker the tool, the slower the rotation speed and the lower the pump discharge amount, and conversely, the thinner the tool thickness, the faster the rotation speed and the larger the pump discharge amount. On the other hand, the required flow rate of cutting oil increases as the diameter of the tool increases, so the diameter of the tip end of the oil hole is formed to be larger as the tool becomes thicker, and narrower as the tool becomes thinner. In short, the discharge flow rate of the pump and the required flow rate at the cutting edge are inversely proportional.

In other words, depending on the diameter of the tip of the tool's oil hole, the flow rate can be adjusted to a certain extent to suit the tool, but due to fluctuations in rotational speed or differences in the diameter of the oil hole between manufacturers, etc. Due to differences in various conditions, it is difficult to supply an appropriate flow rate.

Particularly when a tool with a small tip diameter of the oil hole is installed, the oil pressure inside the device increases more than necessary due to the small tip diameter of the oil hole and the high rotation speed. This also causes problems such as excessive loads being applied to the oil passages.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes a cylindrical rotating shaft into which a cutting tool having a cutting oil hole is inserted and fixed, and a unit that rotatably supports the rotating shaft. A cutting oil intake section connected to an external cutting oil supply section is provided in the unit case, a cutting oil passage from the intake section to the oil hole of the tool is provided in the unit case and the rotating shaft, and the unit case is connected to the machine. In a cutting tool holding device that is fixed to a frame and interlocks and connects a rotating shaft to a rotating main shaft of a machine, a cutting oil passage in a unit case is provided with a pressure boosting pump that is linked to the rotating shaft, and a cutting oil flow rate adjustment mechanism is provided, As the flow rate adjustment mechanism, one side of the pump is covered with an axially movable pump side plate, the side plate is pressed against the rotating body by a spring, and when the pressure is high, the side plate is pushed apart in the axial direction by the hydraulic pressure inside the pump, and the side plate is expanded from the pump discharge port. Excess oil is returned to the intake port.

(Embodiment) In FIG. 3, 1 is a machine such as a machining center with ACT, and a rotating main shaft 4 is rotatably supported on a frame 2 of the machine. A front-opening tapered hole 5 is formed in the front part of the rotating main shaft 4, and a pair of drive claws 7 that protrude forward is formed at the front end edge of the rotating main shaft 4. Both drive claws 7
are arranged on the same circumference centered on the axis of the main rotating shaft 4, and are arranged with a phase difference of 180°. The rotating main shaft 4 of the machine 1 is controlled so as to stop with the drive claws 7 positioned at both the upper and lower ends, for example. A stopper block 10 that projects forward is fixed to the front surface of the lower part of the frame 2, and the stopper block 10 is provided with a stopper hole 11 that opens in the front, and is provided with a valve push rod 13 that projects forward. It is being The rod 13 is urged forward by a coil spring.
An oil supply passage 12 communicates with the rear end of the stopper hole 11, and an inlet of the oil supply passage 12 is connected to a cutting oil supply pump 14.
is connected to.

The tool holding device 15 includes a rotating shaft 16 for holding tools.
A unit case 17 rotatably supports a rotating shaft 16, a stopper pin 18 for positioning the case, and a clutch mechanism 19.

The rotary shaft 16 is integrally provided with a large-diameter collar portion 20 at its rear end, and is further integrally provided with a tapered handle portion 21 extending rearward, and the tapered handle portion 21 is fitted into and connected to the taper hole 5 . An annular gripping groove 22 for a fork that opens in the radial direction on the outer peripheral surface of the large-diameter brim portion 20
is formed, and when replacing the holding device 15, the gripping groove 22 is gripped by a manipulator fork. Also, the large diameter brim 20
has a pair of notched grooves 25 that engage with the drive pawl 7.
are formed, and the drive pawl 7 and the notch groove 2
Power is transmitted from the rotating main shaft 4 to the rotating shaft 16 via the rotary shaft 5.

A tapered hole 2 for mounting a tool is provided at the front end of the rotating shaft 16.
4 is formed, and a rotary cutting tool 26 such as a drill is connected to the tapered hole 24 through a tapered fit. Tool 2
A cutting oil hole 32 is formed in the axial center of the tool 26 and extends to the front cutting edge of the tool 26. It is open at the cutting edge.

The stopper pin 18 extends rearward parallel to the rotating shaft 16, and its rear end portion is inserted into the stopper hole 11.
They are removably fitted together via a ring 14. Further, the stopper pin 18 is formed in a hollow shape and is used as a cutting oil intake portion.

That is, an oil intake port 18a is formed at the rear end edge of the pin 18, a ball valve 23 for opening and closing the intake port is inserted into the pin 18, and a coil spring 30 is compressed to reduce the elasticity of the coil spring 30. Ball valve 2 due to force
3 is seated at the intake port 18a. 33
is a plug and fixing member for the pin 18, the rod portion of which is inserted into the pin 18 via an O-ring, and the flange portion 33a is fixed to the unit case 17 with bolts or the like. The inside of the stopper pin 18 communicates with the annular oil passage 28 of the unit case 17 via the oil hole 34, and the annular oil passage 28 communicates with the oil passage 29.
It communicates with the oil sump 58 via.

The clutch mechanism 19 includes a pin 40 fixed to the rotating shaft 16, a clutch bush 37 slidably fitted to the stopper pin 18, and a notch 4 integrally formed in the bush 37 via an arm 36.
It consists of 2nd class. The notch 42 is the pin 4
0 from the front, and the bush 37 is attached to the rear by a clutch spring 38. Reference numeral 43 denotes a detent pin, which is provided on the rear surface of the unit case 17 in a rearwardly protruding manner and is engaged with the engagement hole of the arm 36.

In FIG. 2, a pressure increasing gear pump 44 is provided in the case 17, and an inlet 56 of the pump 44 communicates with an oil reservoir 58 via an oil passage 45.
The discharge port 59 of the pump 44 is connected to the oil passage 6 of the case 17.
0, the annular oil passage 30 and the oil passage 47 of the rotating shaft 16 shown in FIG.

The pump 44 is connected to the drive gear 5 as shown in FIG.
2 and a driven gear 53 that meshes with the driven gear.
As shown in FIG. 1, the shaft portion 52a of the drive gear 52 is rotatably supported by the case 17 via a bearing, and is integrally provided with an input gear 51. The input gear 51 is connected to the power take-off gear 50. The power take-off gear 50 is fixed to the rotating shaft 16.

The cutting oil flow rate adjustment mechanism includes an axially movable pump side plate 54 and a pair of cone springs 55.
is used. That is, the side plate 54 fits into the driving gear shaft portion 52a and the driven gear shaft portion 53a (FIG. 2) with a moderate amount of play, or in other words, the side plate 54 fits slightly from the vertical position as shown in FIG. The spring 55 is compressed between the side plate 54 and the pump lid 61, and the pump side plate 54 is connected to the spring 5.
5 is pressed against the drive gear side (rear side).

(Function) First, when installing the holding device, the tapered handle portion 21 is fitted and connected to the tapered hole 5 of the rotating main shaft 4, and the stopper pin 18 is inserted into the hole 11 of the stopper block 10. Stopper pin 18
When the rod 13 is inserted into the hole 11, the rod 13 pushes the ball valve 23 to open the intake port 18a, and the oil supply passage 12 and the inside of the stopper pin 18 are communicated with each other. At the same time, clutch button 37 is connected to block 1.
0 and is pushed forward against the clutch spring 38, whereby the clutch pin 40 is removed from the notch 42. That is, the clutch mechanism 19
OFF, and the rotating shaft 16 is connected to the unit case 17.
It is in a state where it can rotate freely against.

During cutting work, the cutting oil sent from the pump 14 in FIG.
Inside the stopper pin 18, oil hole 34, annular oil passage 28
The oil enters the oil reservoir 58 through the oil passage 29, and then enters the pump 44 from the suction port 56 through the oil passage 45 in FIG. 2, where it is pressurized. The pressurized cutting oil enters the hollow portion of the rotating shaft 16 from the discharge port 59 through the oil passage 60, the annular oil passage 30, and the oil passage 47 of the rotating shaft 16. The oil is sent from the hollow part through the oil hole 32 of the tool 26 to the tip of the blade, and the cutting part is lubricated.

In the pump 44, the pressure on the discharge port 59 side is generally high and the pressure on the suction port 56 side is lower than that on the discharge port side.
The forward pressing force on the side plate 54 is not uniform over the entire surface of the side plate 54, and the portion of the side plate 54 near the high-pressure discharge port 59 is pushed forward first. At this time, the gap between both gears 52, 53 and the side plate 54 becomes larger, and the cutting oil travels along the inner surface of the side plate 54 and returns to the suction port 56 side.
The flow rate suitable for
2.

(Another embodiment) (1) The cone spring 55 for adjusting the flow rate shown in FIG. It is also possible to enable the set load to be changed.

(2) As pressure boosting pumps, rotary pumps,
Various rotary pumps such as screw pumps or vane pumps can also be used.

(Effects of the Invention) As explained above, the present invention includes a cylindrical rotating shaft 16 into which a cutting tool 26 having a cutting oil hole 32 is inserted and fixed, and a unit case 17 that rotatably supports the rotating shaft 16. A cutting oil intake part (stopper pin 18) connected to an external cutting oil supply part (cutting oil supply pump 14) is provided in the unit case 17, and a cutting oil passage from the intake part to the oil hole 32 of the tool 26 is connected to the unit case. 17 and the cutting tool holding device provided in the rotating shaft 16, fixing the unit case 17 to the frame 2 of the machine and interlockingly connecting the rotating shaft 16 to the rotating main shaft 4 of the machine: (1) Cutting oil in the unit case 17 Since the pressure increasing pump 44 communicating with the rotating shaft 16 is provided in the oil passage, pressure loss and a decrease in flow rate in the oil passage of the holding device 15 can be prevented.

(2) Since a cutting oil flow rate adjustment mechanism (for example, side plate 54 and spring 55) is provided, an appropriate flow rate is always supplied to the cutting edge of the tool in response to changes in tool thickness, pump rotation speed, etc. can do. As a result, tool life can be improved and cutting efficiency can be improved through smooth removal of chips.

Furthermore, the accuracy of the finished surface and the stability of dimensional accuracy are improved.

(3) As a flow rate adjustment mechanism, one side of the pump is covered with an axially movable pump side plate 54, and the side plate 54
is pressed against the rotating body side by a spring 55, and when the pressure is high, the side plate 54 is expanded in the axial direction by the hydraulic pressure inside the pump, and excess oil is returned from the pump discharge port 59 to the suction port 56. It can be easily incorporated into the unit case, further improving assembly and compactness. Furthermore, the structure of the flow rate adjustment mechanism is simplified and the cost is reduced.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a holding device to which the present invention is applied (-cross-sectional view in Fig. 2), Fig. 2 is a view of the unit case in the direction of the arrow in Fig. 1, and Fig. 3 is a - cross-sectional view in Fig. 2. , FIG. 4 is a longitudinal sectional view of a conventional example. 4...
Rotating main shaft, 16... Rotating shaft, 17... Unit case, 18... Stopper pin (cutting oil intake part), 44... Pressure boosting pump, 54, 55... Pump side plate, cone spring (flow rate adjustment mechanism).

Claims (1)

[Scope of utility model registration request] It is equipped with a cylindrical rotating shaft into which a cutting tool having a cutting oil hole is inserted and fixed, and a unit case that rotatably supports the rotating shaft, and a cutting oil intake part connected to an external cutting oil supply part is installed in the unit case. A cutting tool holding device in which a cutting oil passage from an intake part to an oil hole of a tool is provided in a unit case and a rotating shaft, the unit case is fixed to a machine frame, and the rotating shaft is interlocked and connected to a rotating main shaft of the machine. , a rotary pressure boosting pump linked to a rotary shaft is provided in the cutting oil path in the unit case, and a cutting oil flow rate adjustment mechanism is provided, and as the flow rate adjustment mechanism,
One side of the pump is covered with an axially movable pump side plate, and the side plate is pressed against the rotating body by a spring, and when the pressure is high, the side plate is pushed apart in the axial direction by the hydraulic pressure inside the pump, draining excess oil from the pump discharge port to the suction port. A cutting tool holding device characterized in that it is designed to be returned to its original position.