JP2021154422A - Machine tool - Google Patents

Abstract

To provide a machine tool which hardly deposits sludge in a coolant tank.SOLUTION: A machine tool includes: a machining device which executes machining of a workpiece in a machining chamber; a chip conveyor 6 which discharges machined waste generated from the workpiece from a storage tank for storing the machined waste together with coolant to the outside of the machine tool; and a coolant device which has a suction pipe 31 which repeatedly feeds coolant in a coolant tank 21 provided outside the storage tank to the machining chamber side by a coolant pump 23, is arranged at a corner of the coolant tank bottom, and sucks coolant flowed in from a plurality of suction ports 311 which are formed by the coolant pump.SELECTED DRAWING: Figure 2

Description

The present invention relates to a machine tool that makes it difficult for sludge to accumulate in a coolant tank.

In machine tools, chips and chips generated from the machined work are washed away by coolant, stored in a storage tank under the machine, and discharged to the outside by a conveyor. In addition, chips are removed, and the coolant stored in the coolant tank is sucked up by a pump, filtered by a filter, and sent to a processed part or a cleaning place again. However, due to the repeated use of such coolant, sludge accumulates in the coolant tank, and it is necessary to perform regular cleaning to remove it. Cleaning the sludge requires pulling out the coolant tank from the machine tool, but it also requires removing the chip conveyor and the like, which is a very laborious and time-consuming task.

Therefore, machine tools are required to reduce the number of times the coolant tank is cleaned. That is, it is necessary that sludge is less likely to be accumulated in the coolant tank, but Patent Document 1 below discloses a configuration in which sludge accumulation in the coolant tank is suppressed by a stirring action on the coolant. Specifically, it is a U-shaped coolant tank in which the first coolant tank and the second coolant tank communicate with each other by a communication portion, and the coolant pumped by the supply pump of the second coolant tank is sent to the first coolant tank. The coolant is allowed to flow to the first coolant tank again through the communication portion. In addition, a stirring nozzle body for discharging the coolant is provided so that momentum is added to the flow of the coolant.

Japanese Unexamined Patent Publication No. 2018-199178

However, in the above-mentioned conventional example, the shape of the coolant tank is special, and a plurality of pumps and agitating nozzle main bodies are provided therein. Therefore, such a coolant tank can be implemented as long as it is a large machine tool that can be installed without being affected by other devices, but the machine tool is restricted by the shape of the coolant tank and the relationship with other devices. Is not feasible. For example, a coolant tank in which a chip conveyor is incorporated has a low degree of freedom in shape, and there is no space for installing a plurality of pumps or agitating nozzle bodies. Therefore, even if the coolant tank has many restrictions such as shape, it is desired to have a structure in which sludge does not easily accumulate inside the coolant tank.

Therefore, an object of the present invention is to provide a machine tool that makes it difficult for sludge to accumulate in a coolant tank in order to solve such a problem.

The machine tool according to the present invention includes a processing device that executes processing on a work in a processing chamber, a chip conveyor that discharges processing waste generated from the work together with coolant from a storage tank to the outside of the machine, and the outside of the storage tank. The coolant in the coolant tank provided in the above is repeatedly sent to the processing chamber side by a coolant pump, and the coolant that is arranged at the corner of the bottom of the coolant tank and flows in from a plurality of suction ports formed in the coolant pump is the coolant pump. It has a coolant device with a suction pipe that is sucked into.

According to the above configuration, in the coolant tank provided on the outside of the storage tank, a suction pipe for sucking the coolant toward the coolant pump side is arranged at the corner of the bottom of the tank, so that the coolant at that position is discharged from the suction port. Since it enters the suction pipe and is sucked up by the coolant pump, it is possible to prevent sludge from accumulating in the corner where the coolant tends to stagnate.

It is a perspective view of the internal structure which showed one Embodiment of a machine tool. It is a perspective view which showed the coolant tank of a machine tool. It is a top view of the coolant tank which showed the part of the coolant apparatus simplified. It is a perspective view of the coolant tank which showed the modification of the suction pipe. It is a top view of the coolant tank which showed the part of the coolant apparatus simplified. It is a perspective view which showed the reference example about the coolant tank of a machine tool. It is a top view of the coolant tank which showed the part of the coolant apparatus simplified about the reference example.

An embodiment of a machine tool according to the present invention will be described below with reference to the drawings. In this embodiment, a machining center will be described as an example of a machine tool. FIG. 1 is a perspective view of an internal structure showing the machining center. The entire machining center 1 is covered with an airframe cover (not shown), and a machining chamber 10 indicated by a dotted chain line for performing cutting of a workpiece or the like is configured inside the machining center 1. The machining center 1 is assembled on the movable bed 11 and has a structure that can move in the front-rear direction on the base 2.

The machining center 1 is provided with a spindle head 12 for holding a tool at the front portion, includes a spindle chuck 13 to which a tool such as a drill can be attached and detached, and is configured such that the attached tool is rotated by a spindle motor 14. The spindle head 12 is mounted on the machining drive device 3 so that the spindle head 12 can move in three axial directions due to machining, parts replacement, or the like. The machining drive device 3 is equipped with an X-axis slide 16 that moves in the width direction of the machine body with respect to a Y-axis slide 15 that moves in the vertical direction, and a Z-axis slide 17 that moves in the front-rear direction of the machine body with respect to the X-axis slide 16. Is installed. The movement of each slide is configured to convert the rotational output of the servomotor into a linear motion by a ball screw mechanism.

Below the spindle head 12 that is moved by the machining drive device 3, a chuck device 18 that rotatably grips the work and a tool magazine 19 on the inner side of the machine are incorporated. The tool magazine 19 houses a plurality of tools between the chuck device 18 and the spindle head 12, and an automatic tool changer is incorporated inside the opening / closing door. The machining center 1 is equipped with a spindle head 12, a chuck device 18, a machining drive device 3, and a control device 5 for controlling the drive of the tool magazine 19.

In the machining center 1, coolant is used for lubrication and washing away chips during workpiece processing, and therefore, as shown in FIG. 2, a coolant tank 21 for storing the used coolant is provided in the base 2. As shown by the alternate long and short dash line, the machining center 1 has a chip conveyor 6 incorporated in the coolant tank 21 that separates chips from the coolant and carries them out of the machine. The chip conveyor 6 is connected to a processing chamber 10 in which the work is processed by the input port 601 so that chips generated in the cutting of the work and coolant used for cleaning can enter and be stored from the input port 601. It has become.

The chip conveyor 6 has an endless belt conveyor that conveys chips, and in particular, is provided with a horizontal conveyor that serves as a storage tank for transmitting chips toward the rear of the machine, and further extends diagonally upward to the rear of the conveyor. Is configured as an ascending conveyor that feeds upwards. Therefore, in the chip conveyor 6, the chips accumulated in the storage tank are sent to the rear of the machine body by the belt conveyor, only the chips are carried in the inclined portion that climbs the ascending transport portion, and the coolant that flows down is returned to the storage tank. Since the belt conveyor is folded back at the top, the chips fall naturally and are collected in the collection box installed below.

By the way, the coolant tank 21 is designed to store the coolant that has flowed out of the storage tank of the chip conveyor 6. The storage tank is formed with a drop opening that is closed with a punching metal having fine holes. Therefore, the coolant that overflows and flows out from the drop port is stored in the coolant tank 21 in a state where chips are removed. The machining center 1 is provided with a coolant device that filters such used coolant and repeatedly sends it back into the machine. FIG. 3 is a plan view of a coolant tank showing a part of the coolant device in a simplified manner.

In the coolant device, a pump chamber 22 surrounded by a side wall 221 is formed at a corner of a coolant tank 21, and a first coolant pump 23 is installed therein. A suction window 222 in which a mesh plate is fitted is formed on the side wall 221 so that the coolant in the coolant tank 21 is drawn into the pump chamber 22 by the drive of the first coolant pump 23 and then sucked up. A cyclone filter 25 is connected to the first coolant pump 23 so that the used coolant can be divided into a clean liquid and a dirty liquid. In the cyclone filter 25, the coolant pressurized by the first coolant pump 23 is supplied, sludge is pushed to the wall surface by the centrifugal force of the generated vortex, and the coolant accumulated in the lower part is discharged as a dirty liquid. The coolant that has risen in the center is configured to be discharged as a clean liquid.

In the coolant device, a clean tank 26 for storing clean liquid, a dirty tank 27 and a settling tank 28 are formed, and in the cyclone filter 25, the clean tank 26 is connected to a filtrate port located at the upper part and a drain located at the lower part. A settling tank 28 is connected to the port. Then, a second coolant pump 29 is installed in the clean tank 26, and the coolant that has become the clean liquid is sent into the machine of the machining center 1 and reused for lubrication and washing out chips in the machining.

On the other hand, the settling tank 28 is divided into two chambers by the partition plate 285, the dirty liquid sent from the cyclone filter 25 flows into the settling portion 281 and the coolant that has passed over the partition plate 285 flows into the intermediate portion 282 on the dirty tank 27 side. It flows. A mesh plate 286 is provided between the intermediate portion 282 and the dirty tank 27 so that foreign matter can be removed from the coolant flowing from the intermediate portion 282 to the dirty tank 27. A notch is formed in the upper part of the side wall facing the coolant tank 21 in the dirty tank 27 and the clean tank 26, and the overflowed coolant returns to the coolant tank 21 not only from the dirty tank 27 but also from the clean tank 26. There is.

Therefore, in the coolant device of the machining center 1, chips and the like mixed with the coolant remain in the settling tank 28 and accumulate, so that sludge can be efficiently removed by cleaning the settling tank 28 on a regular basis. However, not all of the chips and the like mixed in the coolant are sucked up by the first coolant pump 23 and flow to the cyclone filter 25, and a part of them remains in the coolant tank 21. In particular, the corner 210 in the coolant tank 21 where the side surface and the bottom surface are orthogonal to each other is a place where the flow velocity drops and the coolant stagnates, so that sludge is likely to accumulate. Therefore, the coolant tank 21 also needs to be cleaned regularly, but since the structure is such that the chip conveyor 6 is incorporated, cleaning by removing the coolant tank 21 from the base 2 is a difficult task.

Therefore, in the present embodiment, a configuration for extending the cleaning cycle for the coolant tank 21 is adopted. That is, as shown in FIGS. 2 and 3, the suction pipe 31 extends in two directions from the pump chamber 22 provided at one corner of the coolant tank 21 along the corner 210 of the coolant tank 21. In the present embodiment, the suction pipe 31 is installed only in the region on the rear side of the machine body where the ascending transport portion of the chip conveyor 6 is located. The suction pipe 31 is as shown by the alternate long and short dash line in FIG. It may be extended to the front side of the machine (lower side of the drawing).

The suction pipe 31 is a square pipe, and is inserted into the inside of the pump chamber 22 so that one end of the opening penetrates the side wall 221 and is fixed to the bottom surface or the side surface of the tank by fastening with bolts, for example. A plurality of suction ports 311 are formed on the upper surface of the suction pipe 31 and the inner side surface of the tank when the suction pipe 31 is fixed, and the suction port 311 is also formed on the closed end surface at the end opposite to the pump chamber 22. ing. Therefore, when the first coolant pump 23 is driven, chips and the like are sucked into the suction pipe 31 together with the coolant from the suction port 311 by the suction force, and flow into the pump chamber 22 through the suction pipe 31. ..

Therefore, in the machining center 1, the coolant flowing out from the storage tank of the chip conveyor 6 is stored in the coolant tank 21, and is sucked up by the first coolant pump 23 and sent to the cyclone filter 25 and the like. At that time, since the suction pipe 31 is provided in the corner 210 where sludge is likely to be accumulated, chips and the like are also sucked from the suction port 311 together with the coolant and sucked up by the first coolant pump 23. Chips and the like are sent from the cyclone filter 25 as a dirty liquid and stored in the settling section 281. At this time, more chips and the like in the coolant tank 21 are carried to the settling portion 281, so that the cleaning cycle of the coolant tank 21 can be extended according to the present embodiment.

The suction pipe 31 can be easily and inexpensively manufactured by using a commercially available square pipe, and the conventional machine tool can achieve the above effect by adding a simple configuration of the suction pipe 31. .. On the other hand, the shape of the suction pipe 31 is not limited to a square pipe having a quadrangular cross section, and may be a suction pipe 33 composed of a pipe having a triangular cross section as shown in FIG. A square pipe such as the suction pipe 31 has a new corner between the side surface and the bottom surface of the coolant tank 21. In this respect, the suction pipe 33 can eliminate corners orthogonal to the coolant tank 21. Then, since chips and the like are sucked together with the coolant from the suction port 331 formed on the slope of the suction pipe 33, the sludge accumulation suppressing effect can be further enhanced.

Like the suction pipe 31, the suction pipe 33 may be extended to the front side of the machine body in the coolant tank 21 as shown by the alternate long and short dash line in FIG. However, as the suction pipes 31 and 33 become longer, the suction force at a position far from the first coolant pump 23 becomes weaker. Therefore, the elongated suction pipes 31 and 33 are formed so that the distance between the adjacent suction ports 311, 331 is smaller at a position farther than the position near the first coolant pump 23, and the suction force of the coolant is increased. It is preferable to be able to exert it even at the position of.

Next, as shown in FIGS. 4 and 5, the coolant tank 21 may be provided with a coolant blow pipe 36 via a switching valve 35 connected to the first coolant pump 23. The tip of the coolant blow pipe 36 extends to the bottom surface of the coolant tank 21 and opens along the corner 210 toward the front side of the machining center 1. Therefore, the coolant blow is injected on the side opposite to the position of the first coolant pump 23, and the flow as shown by the arrow of the alternate long and short dash line in FIG. 5 is created. This flow eliminates the stagnation of the coolant in the corner 210, facilitates the flow of chips and the like into the suction pipes 31 and 33, and can more effectively prevent the accumulation of sludge.

Although one embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, a coolant device having a configuration in which a cyclone filter that separates a clean liquid and a dirty liquid is used and a clean liquid is sent into the machine by a second coolant pump has been described. The configuration such as the coolant supply may be different.

Next, a reference example having a common purpose of making it difficult for sludge to accumulate in the coolant tank and having a technical idea different from that of the above-described embodiment will be described. FIG. 6 is a perspective view of a coolant tank showing a reference example thereof, FIG. 7 is a plan view, and the same reference numerals are given to the same configurations as those of the above-described embodiment. Similar to the machining center 1 shown in FIG. 1, the machine tool of this reference example is provided with a coolant tank 51 shown in the base 2 and a chip conveyor 6 is incorporated therein. Then, a coolant device is provided in which the used coolant is filtered and repeatedly sent into the machine again.

As for the coolant device, the first coolant pump 23 is installed in a corner of the coolant tank 51 on the rear side of the machine body. A cyclone filter 25 is connected to the first coolant pump 23 so that the clean liquid of the used coolant is divided into the clean tank 26 and the dirty liquid is divided into the dirty tank 27 side. A second coolant pump 29 is installed in the clean tank 26, and the coolant that has become the clean liquid is sent into the machine of the machining center 1. A settling tank 28 is provided next to the dirty tank 27, and sludge in which chips and the like have settled accumulates therein, and coolant that has passed through the partition plate 285 and the mesh plate 286 flows to the dirty tank 27.

Therefore, since chips and the like mixed in the coolant are accumulated in the settling tank 28, the accumulated sludge can be efficiently removed by cleaning the settling tank 28 on a regular basis. However, in the coolant tank 51, the coolant tends to stagnate at the corner 510 where the flow velocity drops, and sludge tends to accumulate. Therefore, the coolant tank 51 is provided with a flow control plate 53 (531 to 535) for increasing the suction efficiency of the coolant in the first coolant pump 23. The plurality of flow control plates 53 are arranged with curved surfaces for the purpose of creating a flow of coolant in accordance with the rotation direction (counterclockwise direction) of the first coolant pump 23.

The plurality of flow control plates 53 are formed so that the flow control plate 535 at a distant position is formed long and becomes shorter as it approaches the first coolant pump 23 so that the coolant efficiently flows to the first coolant pump 23. The tip of the flow control plate 531 that wraps around the first coolant pump 23 is joined to the tip of the shortest flow control plate 535, and the coolant flows around the first coolant pump 23 in a swirling manner. .. Further, the flow control plate 53 located behind the coolant tank 51 is cut diagonally so that the flow control plates 533 and 534 located in the middle do not interfere with the inclined ascending transport portion of the chip conveyor 6.

In this reference example, the coolant flowing out from the storage tank of the chip conveyor 6 is stored in the coolant tank 21, and the coolant sucked up from there by the first coolant pump 23 is the cyclone filter 25, the clean tank 26, and the dirty tank 27. Will be sent to. At that time, the flow of the coolant in the coolant tank 51 is liable to be turbulent due to the installation of the chip conveyor 6, but it is constant around the first coolant pump 23 due to the provision of the flow control plate 53. Flow is made.

Therefore, the first coolant pump 23 can efficiently draw in the coolant, and the flow of the coolant in the entire coolant tank 51 is improved. As a result, it is possible to prevent sludge from accumulating in the corner 510 where the coolant tends to stagnate. Then, the chips and the like sucked up by the first coolant pump 23 together with the coolant are accumulated sludge in the settling portion 281 as a dirty liquid through the cyclone filter 25. Therefore, according to this reference example, more chips and the like in the coolant tank 51 are carried to the settling portion 281, so that the cleaning cycle of the coolant tank 51 can be extended.

Although the reference example has been described above as another invention related to the present invention, various modifications can be made without being limited to this in order to obtain the same effect.
For example, since the flow control plate 53 (531 to 535) shown in the reference example is an example, the number and shape thereof can be arbitrarily changed depending on conditions such as the position of the coolant pump and the shape of the coolant tank. Further, as in the embodiment of the present invention, the coolant device may have a different configuration such as sludge filtration and coolant delivery into the machine.

1 ... Machining center 3 ... Machining drive 5 ... Control device 6 ... Chip conveyor 12 ... Spindle head 18 ... Chuck device 19 ... Tool magazine 21 ... Coolant tank 22 ... Pump room 23 ... 1st coolant pump 25 ... Cyclone filter 26 ... Clean tank 27 ... Dirty tank 28 ... Sedimentation tank 31 ... Suction pipe 311 ... Suction port

Claims (5)

A processing device that executes processing on the workpiece in the processing chamber,
A chip conveyor that discharges processing waste generated from the work to the outside of the machine from a storage tank that stores it together with coolant.
The coolant in the coolant tank provided on the outside of the storage tank is repeatedly sent to the processing chamber side by the coolant pump, and is arranged at the corner of the bottom of the coolant tank and flows in from a plurality of suction ports formed. A coolant device equipped with a suction pipe in which the coolant is sucked into the coolant pump,
Machine tools with. The machine tool according to claim 1, wherein the suction pipe extends from the coolant pump in two directions and is provided with a predetermined length along a corner of the bottom of the coolant tank. The claim that the suction pipe has a plurality of suction ports formed on the slope of a triangular pipe having a side surface at a corner of the bottom of the coolant tank, a vertical surface along the bottom surface, a horizontal surface, and a slope connecting both sides thereof. 1 or the machine tool according to claim 2. The work according to any one of claims 1 to 3, wherein the plurality of suction ports formed in the suction pipe are formed so that the distance between the suction ports is smaller at a position farther from the position closer to the coolant pump. machine. The machine tool according to any one of claims 1 to 4, wherein the coolant device is provided with a coolant blow that ejects a part of the coolant discharged from the coolant pump into the coolant stored in the coolant tank. machine.

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