Discharge unit

Abstract

To improve finishing quality in a highly viscous fluid application step.SOLUTION: A discharge unit 1 receives a highly viscous fluid having a viscosity of one hundred thousand cp or higher via a predetermined path, discharges the highly viscous fluid toward an object, and includes: a valve body 9; a solenoid 10; and a spring 11 described below. First, the valve body 9 opens or closes a discharge side opening 14. Further, the solenoid 10 has a stator 19 and a movable element 20 which form a magnetic circuit by energizing a coil 18, and the movable element 20 is integrated with the valve body 9. The movable element 20 is moved by energizing the coil 18 to move the valve body 9 in a direction such that the opening 14 is opened. Furthermore, the spring 11 biases the valve body 9 and the movable element 20 in a direction such that the opening 14 is closed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a discharge unit that receives a highly viscous fluid having a viscosity of 100,000 cp or more via a predetermined flow path and discharges it toward an object.

Background Art

[0002] Conventionally, a discharge unit that discharges a highly viscous fluid as described above toward an object is well known and is used, for example, in the process of applying paint or an adhesive to a predetermined workpiece. By the way, a conventional discharge unit opens the discharge-side opening by using compressed air (see, for example, Patent Document 1).

[0003] That is, a conventional discharge unit includes the following valve body, piston, and spring. First, the valve body opens and closes the discharge-side opening. The piston is integrated with the valve body, forms a pressurizing chamber through which compressed air flows in and out, and is slidably supported with respect to the inner peripheral wall of a predetermined cylinder. The spring biases the integrated body of the valve body and the piston in the direction of closing the discharge-side opening.

[0004] With such a configuration, in a conventional discharge unit, by allowing compressed air to flow into the pressurizing chamber, the integrated body is driven in the direction of opening the discharge-side opening against the biasing force of the spring. Also, by allowing compressed air to flow out of the pressurizing chamber, the integrated body is driven in the direction of closing the discharge-side opening by the biasing force of the spring.

[0005] In recent years, in the process of applying a highly viscous fluid as described above, there has been an increasing demand for improving the finished quality such as film thickness and film width, and countermeasures are required.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, the present disclosure mainly relates to a discharge unit, and aims to improve the finishing quality in the coating process of high-viscosity fluids.

Means for Solving the Problems

[0008] The discharge unit of the present disclosure receives a high-viscosity fluid having a viscosity of 100,000 cp or more via a predetermined flow path and discharges it toward an object, and includes the following valve body, solenoid, and spring. First, the valve body opens and closes the discharge-side opening. The solenoid has a stator and a mover that form a magnetic circuit when current is applied to the coil. The mover is integrated with the valve body, and when current is applied to the coil, the mover moves, thereby moving the valve body in a direction to open the discharge-side opening. Further, the spring biases the valve body and the mover in a direction to close the discharge-side opening. Thereby, according to the discharge unit of the present disclosure, the finishing quality in the coating process of high-viscosity fluids can be improved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the embodiments for carrying out the invention will be described based on examples. It goes without saying that the examples disclose specific examples, and the present invention is not limited to the examples.

Example

[0011] 〔Configuration of the Example〕 The discharge unit 1 of the example will be described with reference to the drawings. The discharge unit 1 receives a highly viscous fluid having a viscosity of 100,000 cp or more via a predetermined flow path and discharges it toward an object (not shown). Further, the highly viscous fluid discharged by the discharge unit 1 is, for example, a paint or an adhesive used in the manufacturing process of an automobile, and the discharge unit 1 discharges such a highly viscous fluid at a pressure in the range of, for example, 1 Mpa or more and 20 Mpa or less.

[0012] Further, the discharge unit 1 constitutes a discharge device 6 together with the following tank 2, pump 3, pressure regulating unit 4, robot 5, etc. (see FIG. 1). Here, the tank 2 stores a highly viscous fluid, and for example, can store 20 liters or more of the highly viscous fluid. The pump 3 sucks and pressurizes the highly viscous fluid from the tank 2 and discharges it, and the pressure regulating unit 4 receives the highly viscous fluid discharged from the pump 3 and regulates the pressure to a predetermined pressure. The discharge unit 1 is, for example, assembled to the pressure regulating unit 4 to form an integral body with the pressure regulating unit 4 and receives the highly viscous fluid pressure-regulated by the pressure regulating unit 4.

[0013] The robot 5 is, for example, a six-axis articulated type and has a well-known structure. The integral body of the discharge unit 1 and the pressure regulating unit 4 is mounted at the tip of the robot 5 and moves three-dimensionally or rotates around the sixth axis. The discharge side of the pump 3 and the receiving side of the pressure regulating unit 4 are connected by a flexible hose 7, and the highly viscous fluid is supplied from the pump 3 to the pressure regulating unit 4 via the hose 7. Hereinafter, the discharge unit 1 will be described in detail with reference to FIGS. 2 to 6.

[0014] The discharge unit 1 of the embodiment includes the following valve body 9, solenoid 10, spring 11, flow path forming portion 12, etc., and is provided in a substantially quadrangular prism shape. First, the valve body 9 opens and closes the opening 14 on the discharge side, and is assembled so that its central axis coincides with the central axis X of the discharge unit 1. Further, the valve body 9 is a cylindrical long rod, and forms a valve portion 9a at the tip that opens and closes the opening 14, and opens and closes the opening 14 by moving in its longitudinal direction.

[0015] In addition, a screw shaft portion 9b is provided at the rear end of the valve body 9 and protrudes rearward. The screw shaft portion 9b is used for fastening with a spring retainer 15 as described later. Here, the spring retainer 15 is also fastened to the output shaft 16 of the solenoid 10 as described later. For this reason, the valve body 9 can move to the other end side in the axial direction by the magnetic attraction force generated by the solenoid 1 and open the opening 14. Note that the valve body 9 is provided, for example, with high-speed tool steel as a material.

[0016] Hereinafter, the direction of the central axis X of the discharge unit 1 is defined as the axial direction, and the side where the valve portion 9a closes the opening 14 and the side where the valve portion 9a opens the opening 14 are defined as one end side and the other end side in the axial direction, respectively. Further, the direction perpendicular to the central axis X of the discharge unit 1 is defined as the radial direction, and the side away from the central axis X and the side approaching the central axis X are defined as the outer peripheral side and the inner peripheral side in the radial direction, respectively.

[0017] The solenoid 10 has a coil 18, a stator 19, and the above-described mover 20, and moves the mover 20 by forming a magnetic circuit passing through the stator 19 and the mover 20 by energizing the coil 18. Further, the mover 20 is integrated with the valve body 9 together with the spring retainer 15, and when the mover 20 moves by energizing the coil 18, the valve body 9 is moved in the direction of opening the opening 14 (to the other end side in the axial direction). Note that the solenoid 10 is provided in a cylindrical shape and is assembled to the other end side in the axial direction of the valve body 9 so that its central axis coincides with the central axis X of the discharge unit 1.

[0018] Further, the solenoid 10 is housed in a space formed by the following housing 21, pedestal 22, etc. Note that the housing 21 and the pedestal 22 form the outer contour of the discharge unit 1 together with the flow path forming portion 12. First, the housing 21 has the following main body portion 21a, bottom wall portion 21b, one - end - side protruding portion 21c, etc. Here, the main body portion 21a and the bottom wall portion 21b are portions that cover the outer peripheral side and the one - end side in the axial direction of the solenoid 1, respectively.

[0019] Also, a hole through which the lead wire of the coil 18 passes is provided in the main body portion 21a, and a receptacle 23 for supplying power to the solenoid 10 is attached. Further, the one - end - side protruding portion 21 is a cylindrical portion that protrudes from the bottom wall portion 21b to the one - end side in the axial direction, and is screwed to the flow path forming portion 12 to form a spring chamber 11a for housing the spring 11.

[0020] Also, the pedestal 22 covers the other end side in the axial direction of the solenoid 1 and is screwed to the other end side in the axial direction of the main body portion 21a. Further, the pedestal 22 forms a portion where the solenoid 1 is fixed by screwing the mounting bolt 24 and the nut 25 described later. Hereinafter, the stator 19 and the mover 20 will be described sequentially.

[0021] The stator 19 is mainly composed of, for example, a base 27 and a case 28 made of a magnetic material. The base 27 is provided in a flange shape and is assembled so as to form a magnetic circuit on the other end side in the axial direction and the inner peripheral side in the radial direction of the coil 18. Also, the case 28 is provided in a cup shape and is assembled so as to form a magnetic circuit on the one - end side in the axial direction and the outer peripheral side in the radial direction of the coil 18.

[0022] A through - hole penetrating in the axial direction is provided at the center of the base 27, and a bearing 16a for supporting the output shaft 16 of the solenoid 10 is mounted in this through - hole. Also, a through - hole is provided at the center of the case 28, and the cylindrical portion 29a of the plunger 29 described later moves on the inner peripheral side of this through - hole. The coil 18 is wound around a predetermined bobbin 30, and is accommodated together with the bobbin 30 in a cylindrical space formed by the base 27, the case 28, the plunger 29, and the like.

[0023] The mover 20 is configured to include the above-described output shaft 16 and the plunger 29. The plunger 29 is made of a magnetic material and is provided in a flange shape. The output shaft 16 penetrates and is fixed to the center of the plunger 29. Then, by supporting the output shaft 16 integrated with the plunger 29 by the bearing 16a, the plunger 29 is assembled so as to form a magnetic circuit on the radially inner peripheral side of the coil 18 and on one axial end side of the case 28.

[0024] Also, the output shaft 16 is assembled so as to coincide with the central axis of the solenoid 10. The tip of the output shaft 16 (that is, one axial end of the output shaft 16) protrudes from the plunger 29. Further, a screw hole 16b used for fastening to a spring retainer 15 described later is provided at the tip of the output shaft 16.

[0025] Also, the rear end of the output shaft 16 (that is, the other axial end of the output shaft 16) protrudes to the other axial end side with respect to the base 27, the case 28, and the pedestal 22. Further, two mounting bolts 24 extend from the base 27 toward the other axial end side, sandwiching the central axis of the solenoid 10. Then, the mounting bolts 24 are screwed and fastened to the nuts 25 as described above, and the entire solenoid 1 is fixed to the pedestal 22 by screwing and fastening the mounting bolts 24 and the nuts 25.

[0026] The spring 11 biases the valve body 9 and the mover 20 in the direction of closing the opening 14 (that is, the one axial end side). Here, the spring 11 is a coil spring provided with spring steel as a material, and is set between the spring retainer 15 and the housing 21. Here, the spring retainer 15 is accommodated in the spring chamber 11a, and has the following screw shaft portion 15b, screw hole 15c, and spring seat 15d together with the main body portion 15a that fits into the inner circumference of the spring 11.

[0027] First, the screw shaft portion 15b is a portion that is screwed into the screw hole 16b of the output shaft 16 and protrudes from the main body portion 15a toward the other end in the axial direction. Further, the screw hole 15c opens at one end in the axial direction of the main body portion 15a and is screwed to the screw shaft portion 9b of the valve body 9. Furthermore, the spring seat 15d is provided so as to expand toward the outer peripheral side at one end in the axial direction of the main body portion 15a and supports one end in the axial direction of the spring 11.

[0028] Also, the other end in the axial direction of the spring 11 is supported by a spring seat 21bs provided on the bottom wall portion 21b of the housing 21. For this reason, the valve body 9 is constantly urged by the spring 11, and when the energization to the coil 18 in the solenoid 1 is stopped, the valve body 9 can move toward one end side in the axial direction by the urging force of the spring 11 to close the opening 14. Note that the spring seat 21bs is provided by recessing the center of the bottom wall portion 21b on the side of the spring chamber 11a toward the other end in the axial direction.

[0029] The flow path forming portion 12 is a portion that forms a flow path for receiving a highly viscous fluid from the pressure regulating unit 4 and sending it to the nozzle 1a of the discharge unit 1. Also, the flow path forming portion 12 supports the valve body 9 so as to be movable in the axial direction and has an opening 14 that is opened and closed by the valve body 9. Further, the flow path forming portion 12 is constituted by the next manifold 33, nozzle adapter 34, and the like. Hereinafter, the manifold 33 and the nozzle adapter 34 will be sequentially described.

[0030] First, the manifold 33 is mainly a component that constitutes a flow path for receiving a highly viscous fluid from the pressure regulating unit 4 and is screwed to the one - end - side protruding portion 21 of the housing 21 so as to close the inner periphery of the one - end - side protruding portion 21 from one end side in the axial direction. Note that the above - mentioned spring chamber 11a is formed by screwing the manifold 33 to the one - end - side protruding portion 21. Also, the manifold 33 has the following accommodation hole 35 and fastening holes 36A, 36B.

[0031] The accommodation hole 35 is provided at the other axial end of the internal space 33a of the manifold 33 and accommodates a group of components for sealing the internal space 33a from the spring chamber 11a. Here, the components accommodated in the accommodation hole 35 are a seal 38, a seal case 38a, a resin washer 38b, etc. The seal 38 is accommodated in the seal case 38a and attached to the outer periphery of the valve body 9, seals the internal space 33a from the spring chamber 11a, and supports the valve body 9 so as to be axially movable.

[0032] Also, the washer 38b is attached to the other axial end side of the seal 38 and accommodated in the seal case 38a to protect the seal 38. An O-ring 39 is attached to the other axial end of the seal case 38a, and the O-ring 39 maintains the liquid tightness between the outer peripheral side of the seal case 38a and the spring chamber 11a.

[0033] The fastening hole 36A is provided for receiving the highly viscous fluid from the pressure regulating unit 4. For example, on the side surface of the manifold 33, it opens in three directions around the central axis X, for example, three of the four directions at every 90°. Also, the fastening hole 36A is provided with an internal thread 36Aa used for fastening to an adapter (not shown) provided on the side of the pressure regulating unit 4. Further, a flow path 36Ab that opens into the internal space 33a is connected to the side of the central axis X of the fastening hole 36A. Thereby, the highly viscous fluid received from the pressure regulating unit 4 flows into the internal space 33a.

[0034] The fastening hole 36B is provided for sending the highly viscous fluid from the internal space 33a to the nozzle 1a of the discharge unit 1. It is provided coaxially with the central axis X and opens at one axial end surface of the manifold 33. Also, the fastening hole 36B is provided with an internal thread 36Ba used for fastening to the nozzle adapter 34. Further, the other axial end side of the fastening hole 36B forms the internal space 33a.

[0035] Next, the nozzle adapter 34 is a component that partially enters the manifold 33 and mainly forms a flow path for sending the highly viscous fluid from the internal space 33a of the manifold 33 to the nozzle 1a, and has a cylindrical internal flow path 34a that is coaxial with the central axis X. Here, the internal flow path 34a is provided so as to penetrate the nozzle adapter 34 in the axial direction and communicates with the inner periphery of the nozzle 1a. Further, the internal flow path 34a accommodates a portion that protrudes from the seal case 38a toward one axial end side inside the valve body 9.

[0036] Also, the nozzle adapter 34 is provided with a male thread 34b at the portion that enters the manifold 33, and is fastened to the manifold 33 by screwing the male thread 34b and the female thread 36Ba of the fastening hole 36B. Further, the nozzle adapter 34 partially protrudes from the manifold 33 toward one axial end side, and a male thread 34c is also provided at the protruding portion to fasten the nozzle 1a. Furthermore, a portion 34d on the other axial end side of the male thread 34b inside the nozzle adapter 34 is reduced in a stepped manner and fits into the internal space 33a and abuts against the seal case 38a. And a flow path 34e that communicates the internal space 33a and the internal flow path 34a is provided in the portion 34d.

[0037] Also, the internal flow path 34a has a step 34f at the protruding portion, and the diameter of one axial end side of the step 34f is reduced. And the sheet 41 is assembled to the internal flow path 34a so as to be locked to the step 34f. Here, the sheet 41 is a cylindrical component, and is provided, for example, with tungsten carbide as a material, and is assembled so that its central axis coincides with the central axis X of the discharge unit 1.

[0038] Also, the inner periphery of the sheet 41 forms a flow path for the highly viscous fluid, the end portion on the other axial end side of the sheet 41 forms a seat portion 41b where the valve portion 9a seats and departs, and the inner periphery of the seat portion 41b functions as an opening 14. And when the valve portion 9a seats and departs with respect to the seat portion 41b, the internal flow path 34a is opened and closed. Note that an O-ring 39 is also mounted at the base of the portion protruding from one axial end side inside the nozzle adapter 34, that is, between the male screw 34b and the male screw 34c. The O-ring 39 maintains the liquid tightness between the outer peripheral side of the nozzle adapter 34 and the outside.

[0039] With the above configuration, according to the discharge unit 1, when the energization of the coil 18 starts, a magnetic circuit is formed between the stator 19 and the rotor 20, and the rotor 20 is attracted to the stator 19 and moves toward the other axial end side. As a result, the output shaft 16, the spring retainer 15, and the valve body 9 move integrally toward the other axial end side against the biasing force of the spring 11, and the valve portion 9a opens the opening 14. Thereby, the internal flow path 34a is opened, and the highly viscous fluid flows from the pressure regulating unit 4 into the manifold 33 and the nozzle adapter 34 and is discharged from the nozzle 1a.

[0040] When the energization of the coil 18 stops, the magnetic circuit formed between the rotor 20 and the stator 19 weakens. Therefore, the output shaft 16, the spring retainer 15, and the valve body 9 move integrally toward the one axial end side by the biasing force of the spring 11, and the valve portion 9a closes the opening 14. Thereby, the internal flow path 34a is closed, the discharge of the highly viscous fluid from the nozzle 1a stops, and the inflow of the highly viscous fluid from the pressure regulating unit 4 into the manifold 33 also stops. Further, the rotor 20 moves toward the one axial end side and moves axially away from the stator 19.

[0041] 〔Effects of the Embodiment〕 The discharge unit 1 of the embodiment receives a highly viscous fluid having a viscosity of 100,000 cp or more via a predetermined flow path and discharges it toward an object, and includes the following valve body 9, solenoid 10, and spring 11. First, the valve body 9 opens and closes the discharge-side opening 14. The solenoid 10 has a stator 19 and a mover 20 that form a magnetic circuit when current is applied to the coil 18. The mover 20 is integrated with the valve body 9, and when current is applied to the coil 18, the mover 20 moves, thereby moving the valve body 9 in the direction of opening the opening 14. Further, the spring 11 biases the valve body 9 and the mover 20 in the direction of closing the opening 14.

[0042] Thereby, the finished quality in the application process of the high-viscosity fluid can be improved. That is, compared with the method of driving the valve body 9 by the inflow and outflow of the conventional pressurized air into the pressurizing chamber, the method of driving the valve body 9 by turning on and off the current applied to the coil 18 has higher responsiveness. For this reason, the opening and closing operation of the valve body 9 with respect to the opening 14 can be performed with higher accuracy than before, so that the finished quality can be improved.

[0043] Hereinafter, the method of driving the valve body 9 by the inflow and outflow of the pressurized air into the pressurizing chamber may be referred to as the "pressurized air drive type". Also, the method of driving the valve body 9 by turning on and off the current applied to the coil 18 may be referred to as the "solenoid drive type".

[0044] Further, in the conventional pressurized air drive type, since the piston slides against the inner peripheral wall of the cylinder, maintenance due to wear is required. However, in the solenoid drive type of the embodiment, sliding wear can be reduced, so that maintenance can be omitted. Also, since the pressurized air contains a lot of moisture, according to the pressurized air drive type, the spring 11 is likely to rust and needs to be replaced frequently. On the other hand, in the solenoid drive type of the embodiment, since pressurized air is not used, the spring 11 is less likely to rust and the need for replacement is also low.

[0045] Furthermore, in the compressed air driven type, grease is used to reduce sliding wear, so the grease is easily scattered along with the flow of compressed air. For this reason, depending on the manner of application, it may have a negative effect on the finished quality. In contrast, in the solenoid driven type of the embodiment, sliding wear can be reduced, so there is no need to use grease, and there is no negative effect caused by grease scattering.

[0046] In addition, since the moving speed of the valve body 9 in the solenoid driven type is significantly higher than that in the compressed air driven type, the material of the valve body 9 is preferably tool steel, and for example, high-speed tool steel is preferably used as described above. In addition, the material of the sheet 41 is preferably mainly made of tungsten carbide as described above.

[0047] The discharge device 6 of the embodiment includes a tank 2 that stores 20 liters or more of a highly viscous fluid, and the highly viscous fluid is supplied from the tank 2 to the discharge unit 1 via a predetermined flow path, and the discharge unit 1 discharges the highly viscous fluid at a pressure in the range of 1 MPa to 20 MPa. The capacity and discharge pressure of the tank 2 can significantly achieve the effects of the above embodiment.

[0048] [Modifications] Various modifications of the present invention are possible without departing from the gist of the invention. First, according to the discharge unit 1 of the embodiment, the spring chamber 11a that houses the spring 11 is formed between the one-end protrusion 21 of the housing 21 and the manifold 33, but the form of the spring chamber 11a is not limited to this form. The spring chamber 11a may be set on the other axial end side of the stator 19 in the housing 21, and, for example, a member that supports one axial end of the spring 11 may be attached to the output shaft 16, and a portion that supports the other axial end of the spring 11 may be provided on the base 22.

[0049] Also, according to the discharge unit 1 of the embodiment, the integrated body of the output shaft 16, the spring retainer 15, and the valve body 9 was fastened by male and female screw engagement both between the output shaft 16 and the spring retainer 15 and between the spring retainer 15 and the valve body 9. However, a coupling may be used for fastening either one or both of them.

[0050] Also, according to the discharge unit 1 of the embodiment, the sheet 41 was accommodated in the nozzle adapter 34. However, a flow path for a highly viscous fluid may be provided so that it can be accommodated in the manifold 33. Furthermore, an opening for dissipating the heat generated by the solenoid 10 may be provided, for example, in the main body portion 21a of the housing 21.

Description of Reference Numerals

[0051] 1 Discharge unit 9 Valve body 10 Solenoid 11 Spring 14 Opening (discharge-side opening) 18 Coil 19 Stator 20 Rotor

Claims

1. A discharge unit that receives a highly viscous fluid having a viscosity of 100,000 cp or more through a predetermined flow path and discharges the fluid toward a target object, A valve body that opens and closes an opening on the discharge side; a solenoid having a stator and a movable element which form a magnetic circuit when a current is passed through a coil, the movable element being integrated with the valve body, and the movable element being moved when a current is passed through the coil, thereby moving the valve body in a direction to open the opening on the discharge side; a spring that biases the valve body and the movable element in a direction to close the discharge side opening.

2. A discharge unit according to claim 1; a tank for storing 20 liters or more of the highly viscous fluid; The highly viscous fluid is supplied from the tank to the discharge unit via a predetermined flow path; The discharge device is characterized in that the discharge unit discharges the highly viscous fluid at a pressure in the range of 1 MPa to 20 MPa.

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