JPH11165235A - Cutting liquid supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate time delay in suction and recovery of remaining cutting liquid in a cutting liquid supply device of machine tool. SOLUTION: In a cutting liquid supply device for machine tool provided with a supply pipe line 19 extending from a cutting liquid supply source 15 to a rear part of a main spindle 5, a recovery pipe line 25 which is branched from the supply pipe passage and reaches a cutting liquid supply source, and a control valve 23 which is provided in the recovery pipe line and controls opening and closing of flow of a cutting liquid, a suction means 21 which generates a negative pressure in a main spindle passage 11 inside the main spindle 5 by injecting the cutting liquid when the control valve 23 is opened and suctions the cutting liquid remaining in the main spindle passage 11 inside the main spindle 5 is provided at a branch point of the supply pipe line and the recovery pipe line 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cutting fluid supply device for a machine tool such as a machining center.

[0002]

2. Description of the Related Art In the field of machine tools, machine tools such as a machining center having an automatic tool changer are widely used. Such a machine tool is provided with a tool holder mounting hole formed in a tapered shape at the tip of the main spindle, and the tool holder is fitted by fitting the tool holder mounting hole with the shank of the tool holder on which the tool is mounted. Removably attached to the main shaft.

In such a machine tool, a cutting fluid supply pipe is provided so as to penetrate through the spindle and the tool holder in a direction from the rear part of the spindle to the distal end, and the cutting fluid includes a cutting part through the cutting fluid supply pipe. There is a machine tool provided with a so-called through-spindle type cutting fluid supply device that jets into a processing area. In a machine tool equipped with a through-spindle type cutting fluid supply device, when the tool holder is removed from the tip of the spindle during tool change by the automatic tool changer, the cutting fluid supply line is cut off between the spindle and the tool holder. Then, the cutting fluid remaining in the cutting fluid supply pipe leaks from the divided portion.

[0004] Since the cutting fluid is generally circulated and used between the processing area and the cutting fluid supply device, the cutting fluid contains minute chips. As described above, when the cutting fluid leaks from the cut portion of the cutting fluid supply pipe, the chips adhere to the tapered surface of the tool holder mounting hole of the main spindle and the tapered surface of the shank of the tool holder. The mounting accuracy of the holder decreases. In order to solve this problem, for example, a cutting fluid supply device disclosed in Japanese Patent Application Laid-Open No. HEI 8-118198 by the present applicant removes cutting fluid remaining in a cutting fluid supply pipe inside a main shaft when a tool is changed. Equipped with a suction device.

FIG. 4 shows the cutting fluid supply device of the above publication.
The cutting fluid supply device 41 sucks the cutting fluid from a tank 45 by a pump 47 and supplies the main spindle device 4 via pipes 51 and 53.
Supply 3 A solenoid valve 4 is provided between the pipes 51 and 53.
9 are provided. The solenoid valve 49 is a two-position directional switching valve, and switches the direction of the cutting fluid sucked by the pump 47 between the spindle device 43 and the ejector 61. When the solenoid valve 49 is at the position shown in FIG.
7 is supplied to the ejector 61 via the pipe 57, and the cutting fluid remaining in the main spindle device 43 is sucked by the ejector 61 through the pipes 53 and 55 by the suction action of the ejector 61. Circulating to the tank 45 via 63. In addition, when cutting fluid is supplied to the main shaft device 43, a solenoid type shutoff is provided to prevent the cutting fluid from returning to the tank 45 via the pipeline 55, the ejector 61, and the pipeline 63. A valve 65 is provided.

[0006]

In this cutting fluid supply device, the solenoid valve 49 is urged to the position shown in FIG. 4 when the remaining cutting fluid in the spindle device 43 is collected.
Until the cutting fluid is filled in the conduit 57 from 9 to the ejector 65, no negative pressure is generated in the ejector 28 and the spindle device 43, and no suction action is exhibited. Therefore, during this time, there is a problem that the residual cutting fluid in the spindle device 43 cannot be suctioned and collected. Also, two solenoid valves 4
A control circuit for synchronizing the operation timings of 9, 65 is required.

An object of the present invention is to eliminate the time delay of suction and recovery of residual cutting fluid as in the prior art in the above-described cutting fluid supply device for a machine tool.

[0008]

SUMMARY OF THE INVENTION The above object is achieved by changing the flow of cutting fluid by using two solenoid valves.
This is achieved by switching over by means of two valves, and immediately producing a negative pressure in the suction means and in the interior of the spindle when the cutting fluid is recovered from the interior of the spindle.

That is, according to the first aspect of the present invention, a cutting fluid is supplied from a cutting fluid supply source to a rear portion of the main shaft to flow through a passage inside the main shaft, and the cutting fluid is supplied from a front portion of the main shaft. A cutting fluid supply device that supplies cutting fluid from the cutting fluid supply source to the main spindle, a collection pipeline that branches from the supply duct and collects cutting fluid inside the main spindle, A control valve that is provided in the recovery pipe and controls opening and closing of the flow of the cutting fluid, and is provided at a branch point between the supply pipe and the recovery pipe, and supplies the cutting fluid to the main spindle when the control valve is closed. A cutting fluid supply device, characterized by comprising suction means for injecting the cutting fluid into the recovery pipe line when the control valve is opened to generate a negative pressure and to suction the cutting fluid remaining inside the main shaft. And

[0010] Preferably, the control valve is a rotary valve provided at a branch point between the supply pipe and the recovery pipe, and opening and closing the recovery pipe.

[0011]

According to the present invention, since the suction means is provided at the branch point of the supply pipe and the recovery pipe, both during the supply of the cutting fluid to the spindle device and during the collection of the cutting fluid from the spindle device. while,
Since the cutting fluid passes through the suction means, the suction fluid is always filled with the cutting fluid when sucking the cutting fluid remaining in the spindle device at the time of tool change. The cutting fluid remaining in the spindle device can be sucked without generating a pressure and causing a time delay.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic view of a first embodiment of the present invention, and FIG. 2 is a sectional view of an ejector. In FIG. 1, a spindle device 1 of a machine tool such as a machining center provided with an automatic tool changer (not shown) includes a housing 3 having a substantially cylindrical hollow portion. In the hollow portion of the housing 3, a main shaft 5 having a tapered tool mounting hole at the tip end is rotatably supported via a bearing 7, and a tool holder 9 having a cutting tool mounted in the tool holder mounting hole. Is attached.

In order to eject a cutting fluid toward a machining area including a cutting portion at the tip of a cutting tool, a spindle passage 11 penetrating through the spindle 5 and the tool holder 9 as a cutting fluid supply conduit.
Is provided. The rear end of the main shaft passage 11 is connected to a cutting fluid supply device 13 via a rotary joint (not shown) or the like. The cutting fluid supplied from the cutting fluid supply device 13 flows from the rear end of the main shaft passage 11 toward the front end, and is jetted from the front end of the tool to the machining area.

The cutting fluid supply device 13 includes a cutting fluid tank 15 as a cutting fluid supply source and a pump 17. The cutting fluid sucked by the pump 17 from the cutting fluid tank 15 is supplied to the main spindle passage 1 of the main spindle device 1 via supply pipes 19a, 19b, 19c and a rotary joint (not shown).
1 is connected to the rear end. An ejector 21 as suction means is disposed downstream of the pump 17 in the supply line, in FIG. 1 between the supply lines 19b and 19c, and is connected to the recovery line 25 from the supply line 19 via the ejector 21. Has branched. A solenoid-operated shut-off valve 23 is provided in the recovery pipe 25 as a control valve for controlling the opening and closing of the flow of the cutting fluid in the recovery pipe 25, and the solenoid of the shut-off valve 23 is a control device of the machine tool ( (Not shown).

Referring to FIGS. 2 (a) and 2 (b), the ejector 21 is a generally well-known fluid discharge device, which ejects a fluid at a high speed from a nozzle and generates a negative pressure by a fluid entrainment action. Then, another fluid is sucked and discharged by the negative pressure. The ejector 21 has a hollow main body 21a. The main body 21a has a pump-side port 2 at one end in the longitudinal direction.
1b is formed, and a tank-side port 21d is formed at the other end. The pump-side port 21b communicates with a nozzle 21e extending toward the tank-side port 21d. The main body 21a is further provided with a machine-side port 21c that opens on the side surface of the nozzle 21e. Ejector 2
The supply line 19b is connected to one pump-side port 21b, the supply line 19c is connected to the machine-side port 21c, and the recovery line 25 is connected to the tank-side port 21d.

Next, the operation of the first embodiment will be described. First, while the machine tool is performing cutting, the solenoid of the shut-off valve 23 is energized and the shut-off valve 23 is closed (see FIG. 2B). Pump 1 via supply line 19a
The cutting fluid sucked from the cutting fluid tank 15 by the pump 7 is pressurized to a predetermined pressure by the pump 17 and supplied to the pump-side port 21 b of the ejector 21 via the supply pipe 19. Since the shut-off valve 23 is closed, the cutting fluid is ejected from the ejector 2.
1 does not flow to the recovery pipe 25, and as shown by an arrow in FIG.
c, and circulates to the spindle device 1 via the supply pipe 19c.

When the predetermined cutting process is completed, the rotation of the spindle 5 is stopped, and the tool changing operation starts. At this time, the solenoid of the shutoff valve 23 is demagnetized, and the collection line 2
5 distribution is opened. As a result, the cutting fluid supplied from the pump 17 to the ejector 21 is jetted from the nozzle 21 e in a jet flow in the axial direction thereof, and flows from the tank-side port 21 d to the recovery pipe 25. At this time, the cutting fluid ejected from the nozzle 21e causes the periphery of the nozzle 21e and the
1 generates a negative pressure, the machine side port 21c, the supply line 1
The cutting fluid remaining in the spindle passage 11 provided in the spindle 5 of the spindle device 1 is sucked by the ejector 21 through the ejector 9c,
It is collected in the tank 15 via the collection pipe 25.

For example, after a certain period of time, when all of the cutting fluid remaining in the spindle passage 11 is sucked, air is sucked from the tip side of the spindle 5 and flows into the ejector 21. In this regard,
Similarly, air flows into the ejector 61 in the cutting fluid supply device according to the prior art shown in FIG. However, the inflow air remains without being discharged from the ejector 61 even when the next cutting process is started. Therefore, when the cutting fluid remaining in the spindle device 43 is sucked when the tool is changed, the solenoid 49 is switched, and even if the solenoid valve 65 is opened, the suction force is not immediately generated in the pipe 55, and the ejector 61 is not generated. Causes a delay in a short time.

On the other hand, in the present embodiment, the ejector 21 as the suction means is provided with the collecting pipes 19a, 19b, 19c.
And at the branch point of the recovery pipe 25, the air that has flowed into the ejector 21 as described above, while the tool change is completed and the next predetermined cutting process is executed,
The cutting fluid flowing into the ejector 21 is pushed out to the spindle device 1. Therefore, when sucking the cutting fluid remaining in the spindle device 1 at the time of the next tool change, the inside of the ejector 21 is always filled with the cutting fluid.
When a negative pressure is generated in the spindle 1, the cutting fluid remaining in the spindle passage 11 of the spindle 5 of the spindle device 1 is immediately sucked without delay time, and the cutting fluid leaks when the tool holder 9 is separated from the spindle 5. The tapered surface of the shank of the tool holder 9 and the spindle 5
The contamination of the tapered surface of the tool holder mounting hole is prevented.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the ejector 21 and the control valve 23 in the first embodiment are replaced by a three-way switching ball valve 31 shown in FIG. Other configurations are the same as those of the first embodiment, and in the following description, descriptions overlapping with those of the first embodiment are omitted. 3 and 4
1, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals.

A fluid discharge device or a three-way switching ball valve 31 as a suction means (hereinafter simply referred to as a ball valve)
Has a valve housing 31a having a pump-side port 31b, a machine-side port 31c, and a tank-side port 31d. Pump side port 31b and tank side port 31d
Are provided substantially in a straight line, whereas the machine-side port 31c extends in the transverse direction. In the valve housing 31a, a valve body 33 is provided with a first position (see FIG. 4B) and a second position (see FIG. 4B) around an axis perpendicular to the plane of FIG.
(See (a)). Valve body 3
3 can be driven by a well-known actuator (not shown) such as an electric motor or a solenoid controlled by a control device (not shown) of the machine tool. Valve body 3
3 is a main passage 33a penetrating in the diameter direction,
The main passage 33a and the cross passage 33b communicate with each other through a nozzle passage 33c. The nozzle passage 33c extends at an angle with respect to the central axis of the main passage 33a such that when the cutting fluid flows through the main passage 33a from the pump-side port 31b to the tank-side port 31c, the pressure of the transverse passage 33b becomes negative. Has been established.

Next, the operation of the second embodiment will be described. First, while the machine tool is performing cutting, the ball valve 31
The valve body 33 has a first position, that is, a first passage 33a in which the main passage 33a is directed transversely to the pump-side port 31b and the tank-side passage 31d, and the transverse passage 33b opens to the pump-side port 31b. (See FIG. 4B), the cutting fluid sucked from the cutting fluid tank 15 by the pump 17 via the supply pipe 19a is supplied to the pump side port 3
1b to the machine side port 31c and the supply line 19c
Is supplied to the spindle device 1 via the

When the predetermined cutting process is completed, the rotation of the spindle 5 is stopped, and the tool changing operation starts. At this time, the valve element 33 moves to a second position (see FIG. 4A) rotated by 90 ° counterclockwise in FIG. 4B. Thereby, the main passage 33a is connected to the pump-side port 31.
b and the tank-side port 31d, and the cross passage 33b opens to the machine-side port 31c. The cutting fluid supplied from the pump 17 to the ball valve 31 flows from the pump-side port 31b via the main passage 33a to the recovery pipe 25 from the tank-side port 31d. At this time, the nozzle passage 33c is moved from the main passage 33a in FIG.
As shown in (a), since the cutting fluid is formed obliquely so as to follow the high-speed flow of the cutting fluid in the main passage 33a, the pressure in the nozzle passage 33c, the cross passage 33b, and the pressure in the main shaft passage 11 become negative pressure. . Thus, the cutting fluid remaining in the main shaft passage 11 provided in the main shaft 5 of the main shaft device 1 is supplied to the ball valve 31 via the supply pipe 19c and the machine-side port 31c.
That is, it is sucked by the cutting fluid suction device and collected in the tank 15 through the collection pipe 25.

As in the first embodiment, when the cutting fluid remaining in the spindle passage 11 is sucked, air is also sucked in. However, when the next cutting process is started, the spindle device 1 is turned on. Ball valve 31 depending on the supplied cutting fluid
And the ball valve 31 is immediately filled with the cutting fluid.

In the cutting fluid supply device according to the second embodiment,
Advantageously, the ball valve 31 as a cutting fluid suction device has both functions of the ejector 21 and the shutoff valve 23 in the first embodiment. In particular, since the ejector is generally relatively large, it must be arranged near the cutting fluid tank. However, in order to quickly suck the cutting fluid remaining in the spindle device 1, it is necessary to place the ejector near the rear end of the spindle 5. Advantageously. In the second embodiment, the suction device can be reduced in size by replacing the ball valve 31 having the functions of the ejector 21 and the shut-off valve 25, and can be arranged at the rear part of the main shaft of the machine tool, resulting in an advantageous configuration.

[0026]

According to the present invention, since the suction means is provided at the branch point between the supply pipe and the recovery pipe, the suction means can be supplied to the spindle device and collected during the recovery from the spindle device. During both, since the cutting fluid passes through the suction means, when sucking the cutting fluid remaining in the spindle device at the time of tool change,
Since the suction means is filled with the cutting fluid, the cutting fluid remaining in the main spindle device can be suctioned immediately without generating a negative pressure inside the suction means and the main spindle device without causing a time delay. .

Further, since the suction means also has a function of switching between the supply pipe and the suction pipe, the cutting fluid supply device can be reduced in size, and the suction means can be disposed at the rear portion of the main spindle device. Thus, it is possible to more effectively exert the suction effect.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a cutting fluid supply device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the ejector of FIG. 1;

FIG. 3 is a schematic view of a cutting fluid supply device according to a second embodiment of the present invention.

FIG. 4 is a sectional view of the cutting fluid discharge device of FIG. 2;

FIG. 5 is a schematic view of a cutting fluid supply device according to the prior art.

[Description of Signs] 1 ... Spindle device 3 ... Spindle housing 5 ... Spindle 11 ... Spindle passage 13 ... Cutting fluid supply device 15 ... Tank 17 ... Pump 19a ... Supply line 19b ... Supply line 19c ... Supply line 21 ... Ejector 23 ... shut-off valve 25 ... collection line 31 ... fluid discharge device (three-way ball valve)

Claims (2)

[Claims] 1. A cutting fluid supply device for supplying a cutting fluid from a cutting fluid supply source to a rear portion of a main shaft to flow through a passage inside the main shaft and ejecting the cutting fluid from a front portion of the main shaft. A supply pipe for supplying a cutting fluid from a cutting fluid supply source to the main spindle, a recovery pipe branching off from the supply pipe and collecting the cutting fluid inside the main spindle, and provided in the recovery pipe, A control valve for controlling the opening and closing of the flow, provided at a branch point between the supply pipe and the recovery pipe, supplying cutting fluid to the main shaft when the control valve is closed, and to the recovery pipe when the control valve is opened. A cutting fluid supply device, comprising: suction means for injecting the cutting fluid to generate a negative pressure and sucking the cutting fluid remaining inside the spindle. 2. The cutting fluid supply device according to claim 1, wherein the control valve is a rotary valve provided at a branch point between the supply pipeline and the recovery pipeline, and opens and closes the recovery pipeline.