JP2015066660A - Coolant spray device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coolant spray device which has excellent drip-proof and dust-proof properties, and can be downsized and in which heat and vibration of a motor are hardly transmitted to a case.SOLUTION: A hollow shaft 11 is inserted into a housing 6 and supported rotatably with bearings 12 and 13, a rotating portion of the hollow shaft is sealed with o-rings 14 and 15. Coolant is supplied from an inlet passage 19 through an inlet chamber 10 and a through-hole 18 to a coolant passage 17 of the hollow shaft 11 and sprayed from a nozzle 31 attached to an end portion of the hollow shaft 11. The hollow shaft 11 is rotated by a motor 4 to adjust a rotation angle of the nozzle 31. In an inner wall of a case 2 for storing the motor 4 and the housing 6, a rib 2B is formed, and a space C is formed between the motor 4 and the housing 6; and the case 2. The space C can make it hard for heat and vibration of the motor 4 to be transmitted to the case 2.

Description

  The present invention relates to a coolant injection device for injecting coolant onto a processing part when machining a workpiece using a machine tool.

  In general, when performing machining such as cutting and grinding using a machine tool, supply coolant (cutting fluid, grinding fluid, etc.) to the machining area for lubrication, cooling, chip removal, prevention of welding, etc. However, processing is performed. In such machining, it is desired to appropriately supply coolant to the machining site from the viewpoint of ensuring machining stability and machining accuracy. Therefore, in various automatic machine tools such as NC machine tools and machining centers, there are various types of coolant injection devices that automatically adjust the coolant injection angle in accordance with the progress of processing so as to appropriately inject coolant into the processing site. Proposed. In this type of coolant injection device, the nozzle for injecting coolant is driven by a motor, and the position and angle of the nozzle are adjusted according to tool change, machining progress, etc., so that coolant is accurately injected to the processing site. Like to do.

  Further, since the coolant injection device is exposed to the splash of coolant and chips generated by machining, sufficient drip-proof and dust-proof properties are required for the servo motor, the reduction gear mechanism, etc. that drive the nozzle, Further, since it is necessary to install in a limited space of an automatic machine tool such as a machining center or an NC machine tool, downsizing is desired. In order to meet such a requirement, for example, in Patent Document 1, a hollow shaft forming a coolant flow path is connected to an output shaft of a motor and is driven to rotate, and the coolant injection nozzle is integrated with the hollow shaft. In addition, a coolant injection device that improves drip-proofing and dust-proofing and enables downsizing is disclosed.

JP 2012-228739 A

  The coolant injection device seals the case to improve drip-proof and dust-proof properties, and also reduces the space in the case for miniaturization. Temperature tends to rise. There is a problem in that the case surface that has become hot may be inadvertently touched during inspection. Further, the case may resonate due to vibration during operation of the motor, which may affect the nozzle ejection angle.

  The present invention has been made in view of the above points, and provides a coolant injection device that is excellent in drip-proof and dust-proof properties, enables miniaturization, and makes it difficult to transmit heat and vibration of a motor to a case. The purpose is to do.

In order to solve the above-described problem, an invention according to claim 1 is a coolant injection device including a nozzle for injecting coolant and a motor for adjusting a rotation angle of the nozzle.
A housing, a hollow shaft rotatably and liquid-tightly inserted into the housing and having a coolant passage formed therein; a through hole provided in a side wall of the hollow shaft; and the through hole provided in the housing An inlet passage that communicates with the coolant passage through a case, and a case that houses the housing and the motor,
One end of the hollow shaft and the output shaft of the motor are arranged coaxially and connected,
The motor and the housing are integrated, the integrated motor and the housing are supported by the case via an elastic body, and a gap is formed between the housing and the motor and the case. It is characterized by that.
According to a second aspect of the present invention, there is provided the coolant injection device according to the first aspect, wherein a rib is provided on the case side or the motor and the housing side, and at least a part of the rib is the housing and the motor. The gap is formed in contact with the side or the case side.

According to the coolant injection device according to the first aspect of the present invention, it is possible to reduce the size and reduce the number of parts that need to be sealed, thereby improving the drip-proof property and the dust-proof property. Further, since the housing and the motor are supported via an elastic body and a gap is provided between the housing and the motor, it is difficult for heat and vibration of the motor to be transmitted to the case.
According to the coolant injection device of the second aspect of the present invention, the gap is formed between the housing and the motor and the case by the rib.

It is a longitudinal cross-sectional view of the coolant injection apparatus which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A first embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 1, a coolant injection device 1 according to this embodiment is attached to a numerical control (NC) machine tool such as an NC drilling machine, an NC milling machine, an NC lathe, a machining center, etc. The movable nozzle unit 3 and the motor 4 are accommodated in the case 2 and integrated (unitized). A sensor chamber 5 is formed between the inner end of the case 2 and the movable nozzle unit 4.

  The movable nozzle unit 3 includes a housing 6. The housing 6 has a substantially rectangular parallelepiped outer shape, and has a stepped opening formed of a middle-diameter bore 7A at the center and a large-diameter bore 7B and a small-diameter bore 7C at both ends. A guide member 8 having a guide bore 8A having the same diameter as that of the small diameter bore 7C is liquid-tightly fitted to the large diameter bore 7B. A hollow shaft 11 passing through the housing 6 is rotatably and liquid-tightly inserted into the small diameter bore 7C of the housing 6 and the guide bore 8A of the guide member 8. Thereby, an inlet chamber 10 is formed between the medium-diameter bore 7 </ b> A of the housing 6 and the hollow shaft 11. Tapered portions 7D and 8B connected to the inlet chamber 10 are formed at the step between the medium diameter bore 7A and the small diameter bore 7C and the end of the guide member 8 on the inlet chamber 10 side. The housing 6 can be formed of a suitable material such as a synthetic resin, and can be appropriately hollowed out.

  The hollow shaft 11 is fitted to a bearing 12 fitted to the large diameter bore 7B of the housing 6 adjacent to the guide member 8 and a bearing bore 7E formed at the end of the housing 6 on the small diameter portion 7C side. The bearing 13 is rotatably supported. The hollow shaft 11 and the small diameter bore 7C of the housing 6 and the guide bore 8A of the guide member 8 are sealed by O-rings 14 and 15, respectively. A plurality of O-rings 14 and 15 are provided to form a multistage seal. Furthermore, the housing 6 seals between the hollow shaft 11 by an O-ring 15A disposed between the small diameter bore 7C and the bearing bore 7E. Further, the guide member 8 seals between the hollow shaft 11 by an O-ring 14 </ b> A disposed between the guide bore 8 </ b> A and the bearing 12. The hollow shaft 11 passes through the sensor chamber 5 and extends through the opening 16 provided at the end of the case 2 to the outside of the case 2.

  The hollow shaft 11 is formed with a coolant passage 17 extending along the axial center thereof, and one end of the coolant passage 17 is opened at a tip portion where the hollow shaft 11 extends to the outside of the case 2, and an end portion on the motor 4 side. Is blocked. In addition, a plurality of through holes 18 that allow the coolant passage 17 and the inlet chamber 10 to communicate with each other are passed through the side wall of the hollow shaft 11. An inlet passage 19 communicating with the inlet chamber 10 is provided on the side wall of the housing 6, and the inlet passage 19 protrudes from the housing 6 and extends through the opening 20 provided on the side wall of the case 2 to the outside of the case 2. ing.

A connecting portion 21 is formed at the end of the hollow shaft 11 on the motor 4 side. A coupler 24 that engages with the connecting portion 21 is press-fitted into the output shaft 23 of the motor 4. The tip of the output shaft 23 protrudes through the coupler 24. The connecting portion 21 of the hollow shaft 11 is formed in a convex shape with two chamfered tip portions, and has a forked shape with a bore 21A for receiving the tip portion of the output shaft 23 protruding from the coupler 24 at the center portion. . The coupler 24 is formed in a concave shape having a groove portion for receiving the convex end portion of the connecting portion 21. Then, the rotational force is transmitted between the hollow shaft 11 and the output shaft 23 of the motor 4 by the engagement between the connecting portion 21 and the coupler 24. The motor 4 is coupled to the end of the housing 6 via a coupling member 22 so that the housing 6 and the motor 4 are integrated. The coupling member 22 positions the hollow shaft 11 and the output shaft 23 of the motor 4 coaxially. A space between the coupling member 22 and the housing 6 is sealed by an O-ring 22A. In addition, the shape of the coupler 24 attached to the connecting portion 21 of the hollow shaft 11 and the output shaft 23 of the motor 4 is not limited to the above-described two-chamfered shape, and any shape that can transmit a rotational force between them can be used. Other shapes may be used.

  The motor 4 can control the rotation angle of the output shaft 23 and can be a known servo motor or stepping motor. Further, as the stepping motor, any of a variable reluctance type, a permanent magnet type, or a hybrid type combining these may be used. However, in this embodiment, since the adjustable step angle is sufficiently small, the hybrid type stepping motor is used. A motor is used.

  The housing 6 integrated with the motor 4 is connected to a threaded portion 19A on the outer periphery of the inlet passage 19 that extends through the opening 20 of the case 2 via a sealing material 25 (such as a rubber washer) and a washer 26. The joint 27 is fixed to the case 2 together with the motor 4 by screwing. A gap between the hollow shaft 11 protruding outside from the opening 16 of the case 2 and the opening 16 of the case 2 is sealed by a lip seal 28 attached to the hollow shaft 11.

  An origin position sensor 29 that detects the origin position of the hollow shaft 11 is provided in the sensor chamber 5. The origin position sensor is composed of a magnet holder 29A fixed to the hollow shaft 11 and an element 29B fixed to the case 2 side so as to face the magnet holder 29A, and a magnetic field by a magnet, a Hall element, or the like attached thereto. Based on the change or the like, the origin position of the hollow shaft 11 is detected. Lead wires (not shown) connected to the motor 4 and the origin position sensor 29 are connected to an external control circuit (not shown) via a connector 30 provided on the case 2.

  The case 2 can be provided with an air supply port (not shown) for supplying air into the case 2. By supplying air from the air supply port and maintaining the inside of the case 2 at a positive pressure at all times, coolant is supplied. It is possible to prevent foreign matter such as splashes and fine chips from entering the case 2.

  A nozzle 31 oriented in a direction perpendicular to the hollow shaft 11 is attached to the tip of the hollow shaft 11 that protrudes outward from the case 2. The nozzle 31 is formed by attaching a tapered nozzle body 33 extending in a direction perpendicular to the nozzle holder 32 to a substantially bottomed cylindrical nozzle holder 32 fitted to the hollow shaft 11.

  The substantially bottomed cylindrical nozzle holder 32 has a bore 34 into which the hollow shaft 11 is inserted and fitted, and an enlarged large diameter portion 34 </ b> A is formed at an intermediate portion of the bore 34. A screw hole 35 communicating with the large diameter portion 34 </ b> A is passed through the side wall of the nozzle holder 32. On the outer periphery of the distal end portion of the hollow shaft 11 protruding outside from the case 2, the seal grooves 36 are respectively provided at positions facing both side portions of the large diameter portion 34 </ b> A of the bore 34 when inserted into the bore 34 of the nozzle holder 32. , 37 are formed. O-rings 38 and 39 are mounted in the seal grooves 36 and 37 to seal between the bore 34 and the hollow shaft 11. An annular fixed groove 40 is further formed on the outer peripheral portion of the hollow shaft 11 on the proximal end side with respect to the seal groove 37. On the side wall of the nozzle holder 32, a screw hole 42 is penetrated so as to face the fixing groove 40 of the hollow shaft 11. Then, by inserting the distal end portion of the hollow shaft 11 into the bore 34 of the nozzle holder 32, screwing the set screw 41 into the screw hole 42, and engaging and pressing the distal end portion with the fixing groove 40 of the hollow shaft 11, The nozzle holder 32 is fixed to the hollow shaft 11. The hollow shaft 11 has its distal end abutted against the bottom of the bore 34 to define the insertion position. By inserting the hollow shaft 11 into the bore 34, a nozzle chamber 43 is formed between the large diameter portion 34 </ b> A of the bore 34 and the hollow shaft 11.

  A plurality of nozzle through holes 44 communicating with the nozzle chamber 43 are passed through the side wall of the hollow shaft 11 inserted into the bore 34 of the nozzle holder 32. In the present embodiment, four nozzle through holes 44 are provided at equal intervals along the circumferential direction. The sectional area of each nozzle through hole 44 is smaller than the sectional area of the coolant passage 17 of the hollow shaft 11, and the total sectional area of the plurality of nozzle through holes 44 is larger than the sectional area of the coolant passage 17.

  The nozzle body 33 has a tapered shape and is attached to the nozzle holder 32 by screwing a screw portion 45 formed at the base end portion into the screw hole 35 of the nozzle holder 32. A nozzle passage 46 passes through the nozzle body 33 along the axial direction thereof, the proximal end of the nozzle passage 46 is connected to the nozzle chamber 43, and the distal end opens at the distal end portion of the nozzle body 33. The sectional area of the nozzle passage 46 is smaller than the sectional area of the coolant passage 17 of the hollow shaft 11.

Next, the structure of the case 2 will be described in more detail.
The case 2 houses the movable nozzle unit 3 and the motor 4 in a substantially rectangular parallelepiped box-shaped main body, and seals the inside. In the case 2, a connector portion 2 </ b> A that collects lead wires connected to the motor 4 and the origin position sensor 29 accommodated in the case 2 protrudes from the upper portion of the end portion in FIG. 1. A connector 30 for connecting these lead wires to an external control circuit is attached to the upper end portion of the connector portion 2A.

  On the inner surface of the case 2, a plurality of ribs 2 </ b> B are projected along the longitudinal direction or a direction orthogonal thereto. When the movable nozzle unit 3 (housing 6) and the motor 4 integrally coupled by the coupling member 22 are fixed to the case 2 by the pipe joint 27 via the seal member 25 and the washer 26, at least a part of the ribs A gap C is formed between the housing 6 and the motor 4 and the inner wall of the case 2 by abutting the tip of the 2B against the housing 6 or the motor 4. The movable nozzle unit 3 (housing 6) and the motor 4 integrated by the coupling member 22 are screwed into the threaded portion 19A of the inlet passage 19 and a pipe joint 27 is attached to the case 2 via a sealing material 25 made of an elastic body. Thus, the case 2 is elastically supported. Furthermore, since the movable nozzle unit 3 and the motor 4 are fixed to the case 2 only at one place, the gap C can be easily formed without bringing other portions into contact with the inner wall of the case 2.

  A substantially flat mounting plate 2 </ b> C is integrally formed on the back of the case 2. The mounting plate 2C is provided with a mounting hole 2D having an appropriate shape such as a round hole or a long hole. An appropriate fastener such as a bolt is inserted into the mounting hole 2D so that the coolant injection device 1 can be mounted on a processing machine or the like.

  In the present embodiment, the case 2 is made of synthetic resin in consideration of weight reduction and productivity, but may be made of metal such as aluminum die-cast or other materials. A part of the case 2 may be made of metal.

Next, the operation of the present embodiment configured as described above will be described.
The coolant injection device 1 is attached to an automatic machine tool such as an NC machine tool or a machining center with the nozzle 31 directed in an appropriate direction. The inlet passage 19 is connected to a coolant supply source including a pump and the like via a pipe joint 27, and the motor 4 and the origin position sensor 29 are connected to a control circuit via a connector 30 provided in the case 2. Then, the coolant is supplied from the inlet passage 19 and sprayed through the inlet chamber 10, the through hole 18 and the coolant passage 17, the nozzle through hole 44, the nozzle chamber 43, and the nozzle passage 46 of the nozzle body 33.

  By rotating the output shaft 23 of the motor 4 and controlling the rotation angle of the hollow shaft 11 connected to the output shaft 23, the rotation angle of the nozzle 31 can be adjusted, and the coolant is injected in a desired direction. Can do. The inlet chamber 10 formed in the housing 6 may be omitted, and the coolant may be directly supplied from the inlet passage 19 to the through hole 18 of the hollow shaft 11.

  As a result, the rotation angle of the nozzle 31 is adjusted according to the change in the tool tip position due to the change of the tool of the automatic machine tool or the change in the distance from the nozzle to the machining position due to the progress of machining. It becomes possible to inject the coolant. At this time, since a stepping motor is used as the motor 4, control by an open loop is possible, and the motor drive circuit is simplified as compared with the case of performing control by a closed loop using a servo motor. Can do.

  When controlling the rotation angle of the nozzle 31, in addition to adjusting the nozzle injection angle in order to accurately apply the coolant to the cutting site, a wider angular range so as to remove chips from the processing site by coolant injection By moving the nozzle 31, the removal of chips can be promoted. Further, the rotation of the nozzle can be performed while changing the constant speed or the speed. Further, by using a stepping motor as the motor 4, the control code (so-called M code) for auxiliary operation of the NC machine tool is used as a control signal for the motor 4 to cause the rotation angle of the nozzle 31 to follow the machining site. Since control becomes possible, the control circuit of the coolant injection device can be simplified.

  By circulating the coolant through the coolant passage 17 inside the hollow shaft 11 for rotating the nozzle 31, it is possible to reduce the size of the coolant injection device 1, in particular, to reduce the dimension in the axial direction. The drip-proof property and the dust-proof property can be improved by reducing the amount of the water. In addition, by providing an air supply port in the case 2 and supplying air into the case 2 so that the inside of the case 2 is always at a positive pressure, foreign matter such as coolant splashes and fine chips can enter the case 2. It can be effectively prevented.

  The origin adjustment (zero point adjustment) of the initial position of the rotation angle of the output shaft 23 of the motor 4 (stepping motor) can be performed based on the detection position of the origin position sensor 29 attached to the hollow shaft 11. At this time, the nozzle 31 is fixed to the hollow shaft 11 by the set screw 42 and can be fixed at an arbitrary origin position with respect to the hollow shaft 11 to which the origin position sensor 29 is attached. The origin adjustment of the nozzle 31 can be easily adjusted without changing the fixing position of the sensor 29.

  By making the sectional area of the nozzle passage 46 of the nozzle body 33 sufficiently smaller than the sectional area of the coolant passage 17, the injection pressure can be increased. As a result, the straightness of the injected coolant can be improved, and the coolant can be efficiently supplied to the necessary part.

  At this time, when the coolant flowing through the coolant passage 17 of the hollow shaft 11 flows from the nozzle through hole 44 to the nozzle chamber 43, the direction is changed at right angles, so that an impact force is generated due to the coolant colliding with the inner wall. . However, in the present invention, the coolant flows from the coolant passage 17 through the plurality of nozzle through holes 44 to the nozzle chamber 43 which is a wider space, and the flow velocity decreases, so that the coolant flows into the nozzle passage 46 having a small cross-sectional area. In doing so, the impact force acting on the nozzle body 33 is reduced. In addition, since a sufficient amount of coolant is stored in the nozzle chamber 43 due to the volume of the nozzle chamber 43, the coolant flow to the nozzle passage 46 can be stabilized. In addition, since the total cross-sectional area of the plurality of nozzle through holes 44 is larger than the cross-sectional area of the coolant passage 17 of the hollow shaft 11, the energy when the coolant passes from the coolant passage 17 to the nozzle passage 46 through the through holes 44. Since the loss is suppressed, a sudden pressure drop is suppressed, and the impact force acting by the coolant colliding with the inside of the nozzle chamber 43 is dispersed, so that the nozzle 31 can be prevented from coming off the hollow shaft 11. it can.

  Since the nozzle body 33 reduces the fluid force that acts during the injection of the coolant and does not require high strength, the nozzle body 33 can be manufactured using a synthetic resin or the like, and can be reduced in weight and cost. Since the nozzle body 33 is attached to the nozzle holder 32 by screwing the screw portion 45 into the screw hole 35, the nozzle body 33 can be easily replaced, and the nozzle body 33 can be changed according to the processing machine to be used. The shape of can be changed.

  Since the rib 2B is formed on the inner wall of the case 2 and the gap C is provided between the case 2, the movable nozzle unit 3 (housing 6), and the motor 4, heat due to the operation of the motor 4 is hardly transmitted to the case 2. Thus, the temperature rise of the surface of the case 2 can be suppressed. The motor 4 is cooled by the coolant flowing through the coolant passage 17 of the hollow shaft 11 via the output shaft 23 of the motor 4 connected to the hollow shaft 11. Further, since the integrated movable nozzle unit 3 and the motor 4 are elastically supported by the case 2 via the sealing material 25 made of an elastic body, the gap between the case 2 and the case 2 is reduced. It is difficult for vibration to be transmitted between them, and the influence of vibration can be reduced.

  In the above embodiment, instead of providing the case 2 with the rib 2B, the case 2 and the movable nozzle unit 3 (housing) are provided by providing a rib on the housing 6 and the motor 4 side or winding a band-shaped member. A gap C may be formed between 6) and the motor 4. The case 2 may be partially formed of a heat conductive metal or the like, and the portion may be brought into contact with the motor 4 to radiate heat.

  DESCRIPTION OF SYMBOLS 1 ... Coolant injection apparatus, 2 ... Case, 2B ... Rib, 4 ... Motor, 6 ... Housing, 11 ... Hollow shaft, 17 ... Coolant passage, 18 ... Through-hole, 19 ... Inlet passage, 23 ... Output shaft, 25 ... Seal Material (elastic body), 31 ... nozzle, C ... gap

Further, since the coolant injection device is exposed to the splash of coolant and chips generated by machining, sufficient drip-proof and dust-proof properties are required for the servo motor, the reduction gear mechanism, etc. that drive the nozzle, Further, since it is necessary to install in a limited space of an automatic machine tool such as a machining center or an NC machine tool, downsizing is desired. In order to meet such a demand, for example, Patent Document 1 discloses that a hollow shaft forming a coolant flow path is connected to an output shaft of a motor and rotationally driven, and a coolant injection nozzle is integrated with the hollow shaft. Thus, a coolant injection device that improves drip-proof and dust-proof properties and enables downsizing is disclosed.

The coolant injection device seals the case to improve drip-proof and dust-proof properties, and also reduces the space in the case for miniaturization. Temperature tends to rise. There is a problem that an operator may carelessly touch the surface of the case that has become hot during inspection. Further, the case may resonate due to vibration during operation of the motor, which may affect the nozzle ejection angle.

Claims (2)

In a coolant injection device comprising a nozzle for injecting coolant and a motor for adjusting the rotation angle of the nozzle,
A housing, a hollow shaft rotatably and liquid-tightly inserted into the housing and having a coolant passage formed therein; a through hole provided in a side wall of the hollow shaft; and the through hole provided in the housing An inlet passage that communicates with the coolant passage through a case, and a case that houses the housing and the motor,
One end of the hollow shaft and the output shaft of the motor are arranged coaxially and connected,
The motor and the housing are integrated, the integrated motor and the housing are supported by the case via an elastic body, and a gap is formed between the housing and the motor and the case. The coolant injection apparatus characterized by the above-mentioned.   Ribs are provided on the case side or the motor and the housing side, and at least a part of the ribs contacts the housing and the motor side or the case side to form the gap. The coolant injection device according to claim 1, wherein

Images