Adhesive hand and industrial robots equipped with the adhesive hand

Abstract

A robot suction hand (20) is installed on an industrial robot and sucks a workpiece through a suction part (70). A vacuum pump (30) is built in the robot. The vacuum pump has a shell (31) formed with an air intake port (33a) and an air exhaust port (34a). Air is intermittently sucked from the air intake port and air is intermittently discharged from the air exhaust port. The suction part is connected to the air intake port via a suction passage (61), and a first component (48) formed of a porous material covers the air exhaust port.

Description

Technical Field

[0001] The present invention relates to a suction hand installed on a robot or other equipment, and in particular to a suction hand for a robot suitable for an industrial robot that needs to perform suction operations such as suction of workpieces or other objects. Background Art

[0002] Conventionally, there is a suction hand which is mounted on a robot and sucks and holds a workpiece (see Patent Document 1). The suction hand described in Patent Document 1 is connected to a tube for sucking or exhausting air.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-139835 Summary of the invention

[0006] Technical Problems to be Solved by the Invention

[0007] However, the tube connected to the suction hand is connected to the vacuum pump set at a position away from the suction hand. Therefore, when the robot moves, the tube may be entangled in the robot. However, in order to build the vacuum pump into the suction hand to omit the tube, the vacuum pump must be miniaturized. In addition, it is also desirable to suppress the noise generated by the suction hand.

[0008] An object of the present invention is to reduce the size of a vacuum pump in a suction hand mounted on a robot or other device having a built-in vacuum pump, and to suppress noise generated by the suction hand.

[0009] Technical solutions for solving technical problems

[0010] A first method for solving the above-mentioned technical problem is a robot suction arm, which is installed on the robot and sucks the workpiece through the suction part, wherein a vacuum pump is built in, and the vacuum pump has a shell with an air intake port and an exhaust port, and air is intermittently sucked from the air intake port and intermittently discharged from the exhaust port. The suction part is connected to the air intake port via a suction passage, and a first component formed of a porous material covers the exhaust port.

[0011] In the above structure, the suction hand is mounted on, for example, an industrial robot, and suctions the workpiece by the suction part.

[0012] Here, the vacuum pump has a housing formed with an air intake port and an air exhaust port, and air is intermittently sucked from the air intake port and air is intermittently exhausted from the air exhaust port. The adsorption portion is connected to the air intake port via a suction passage. Therefore, by sucking air from the air intake port, a negative pressure can be formed in the adsorption portion, and the workpiece can be adsorbed by the adsorption portion. The adsorption hand has a built-in vacuum pump. Therefore, there is no need to connect the vacuum pump and the adsorption hand set at a position away from the adsorption hand through a pipe, which can prevent the pipe from being entangled in the robot when equipment such as an industrial robot is in operation.

[0013] Due to the pressure difference of air generated when the vacuum pump intermittently sucks air from the air intake port, a pulsating sound is generated at the air intake port. In addition, due to the pressure difference of air generated when the vacuum pump intermittently discharges air from the air exhaust port, a pulsating sound that is louder than the pulsating sound generated at the air intake port is generated at the air exhaust port. In view of this, the first component formed by a porous material covers the air exhaust port, so that the air is discharged from the air exhaust port via the first component. The air discharged from the air exhaust port passes through a tiny gap formed inside the porous material when passing through the first component. As a result, the pressure difference of the air becomes smaller, and the pulsating sound (noise) generated at the air exhaust port can be suppressed. Furthermore, since only the first component formed by a porous material is used to cover the air exhaust port, the structure for suppressing noise can be simplified, and the vacuum pump can be miniaturized.

[0014] In the second aspect, the first member is formed of a sintered stainless steel material. According to such a structure, the first member can be manufactured at a low cost compared to a so-called muffler of a vacuum pump, and the durability of the first member can be improved.

[0015] In the third aspect, the second member formed of a porous material covers the air intake port.

[0016] According to the above configuration, the second member formed of the porous material covers the air inlet, so that the pulsation sound (noise) generated at the air inlet can be suppressed, and the noise generated by the suction hand can be further suppressed.

[0017] In the fourth aspect, the second member is formed of a sintered stainless steel material. According to such a structure, the second member can be manufactured at a low cost compared to a so-called muffler of a vacuum pump, and the durability of the second member can be improved.

[0018] In the fifth aspect, the exhaust port is formed in a tapered shape that spreads from the inside toward the outside of the casing.

[0019] According to the above configuration, the exhaust port is formed into a tapered shape that expands from the inside of the housing toward the outside. Therefore, the pressure difference between the air in the exhaust port and the air outside the exhaust port can be reduced, and the pulsation sound (noise) generated in the exhaust port can be suppressed.

[0020] In the sixth aspect, the first component is formed into a plate-like shape having the same shape as a predetermined surface of the housing where the exhaust port is formed, and is mounted on the predetermined surface. With such a structure, it is easy to ensure the size of the first component and to easily mount the first component on the predetermined surface of the housing.

[0021] In the seventh aspect, the suction passage is formed in a straight line, and the suction passage, the air intake port, and the air exhaust port are arranged on the same straight line.

[0022] According to the above structure, the suction passage is formed in a straight line. Moreover, the suction passage, the air intake port and the exhaust port are arranged on the same straight line. Therefore, the distance from the adsorption part to the exhaust port can be set to the shortest, and the exhaust efficiency of the vacuum pump can be improved.

[0023] Specifically, as in the eighth aspect, the vacuum pump may be a Roots pump. The Roots pump has a simple structure and can be easily miniaturized. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram showing a robot and a suction hand.

[0025] Figure 2 It is a front cross-sectional view of the adsorption hand.

[0026] Figure 3 This is a side view of the suction hand with the outer shell removed.

[0027] Figure 4 It is a rear view of the suction hand with a portion of the outer shell omitted.

[0028] Figure 5 Schematic diagram showing the state of air passing through a sintered material.

[0029] Figure 6 It is a figure which shows the effect of a 1st component and a 2nd component.

[0030] Figure 7 : is a graph showing the relationship between the roughness of the hole of the second member and the noise.

[0031] Figure 8 : is a graph showing the relationship between the thickness of the sintered material and the sound absorbing effect.

[0032] Description of Reference Numerals

[0033] 10: robot; 20: suction arm (suction arm for robot); 30: vacuum pump; 31: housing; 32: rotor chamber; 33a: suction port; 34a: exhaust port; 41: first rotor (rotor); 42: second rotor (rotor); 45: motor (electric motor); 48: first component; 49: second component; 50: gear mechanism (transmission mechanism); 61: suction passage; 70: suction cup part (suction part); 78: housing. DETAILED DESCRIPTION

[0034] Hereinafter, an embodiment of an industrial multi-joint robot for sucking and transporting a workpiece will be described with reference to the drawings.

[0035] like Figure 1 As shown, the robot 10 sucks the workpiece W placed on the stage 80 with the suction hand 20 and transports it to another place, or lifts the workpiece W in the sucked state and puts the workpiece W on the stage 80 after a certain period of time.

[0036] The robot 10 is, for example, a six-axis vertical articulated robot, and includes a base 11 (a base) and an arm 10A. Adjacent links 13 and 15 (only a portion is shown) of the arm 10A are connected to each other via joints 12, 14, and 16 (only a portion is shown) in sequence so as to be relatively rotatable. Each joint 12, 14, and 16 is driven by a motor (not shown) corresponding to each joint 12, 14, and 16.

[0037] For example, encoders 81, 82, and 83 are provided at the joints 12, 14, and 16 of the robot 10, respectively, to detect the rotation angles of the joints 12, 14, and 16. The encoders 81, 82, and 83 detect the position and posture of the control point of the arm 10A. The control point is set at the center of the top end 18 of the arm 10A. The suction hand 20 is installed at the top end 18 of the arm 10A.

[0038] A control unit 86 for controlling the actions of the robot 10 and the suction hand 20 is provided inside the base 11. The control unit 86 is configured as a computer, and includes elements necessary for controlling the actions of the robot 10 and the suction hand 20, such as a CPU (central processing unit) 86A serving as a computing center, a ROM (read only memory) 86B, a RAM (random access memory) 86C, a drive circuit 86D, and an input / output interface 86E. These elements are connected to each other in a communicative manner through an internal bus 86F, and are connected to the drive circuit 86D through the input / output interface 86E.

[0039] ROM86B is a storage device that functions as a computer-readable non-volatile storage medium (non-transitory computerreadable recording medium), and pre-stores the action programs of the robot 10 and the suction hand 20 in a manner that can be read by CPU86A. RAM86C is configured to temporarily store data during the processing performed by CPU86A. The control unit 86 controls the actions of the robot 10 and the suction hand 20 by executing the program stored in ROM86B through CPU86A. Of course, as long as CPU86A is an element that serves as the computing center of the computer system and has the same function, its name can be different (for example, processor, computing device).

[0040] A plurality of sheet-shaped (thin) workpieces W are placed on the stage 80. The workpieces W are, for example, electronic substrates. It is difficult to grip the sheet-shaped workpieces W with a gripper hand having a pair of gripping claws and to carry them. Therefore, the robot 10 uses the suction hand 20 to suck the workpieces W and carry them.

[0041] Figure 2 It is a front cross-sectional view of the suction hand 20 . Figure 3 It is a side view of the suction hand 20 in a state where the outer shell 78 is removed. Figure 4 FIG. 2 is a rear view of the suction hand 20 with a portion of the housing 78 omitted. Figure 2 As shown, the suction hand 20 (suction hand for robot) includes a vacuum pump 30, a head 60, a suction cup 70, a substrate 73, a connector 76, a housing 78, etc. The suction hand 20 has the vacuum pump 30, the substrate 73, and the connector 76 built therein.

[0042] The vacuum pump 30 is a positive displacement rotary pump, more specifically, a Roots pump, and includes a housing 31 , rotors 41 and 42 , a motor 45 , a gear mechanism 50 , and the like.

[0043] The shell 31 is formed into a rectangular parallelepiped by metal or the like, and a rotor chamber 32 is formed inside. The rotor chamber 32 is a space in which the rotors 41 and 42 are housed and in which the rotors 41 and 42 can rotate. In the shell 31, an intake passage 33 and an exhaust passage 34 are formed to connect the rotor chamber 32 with the outside of the shell 31. The intake passage 33 and the exhaust passage 34 are formed in a straight line and are arranged on the same straight line C. The direction of the straight line C is consistent with the length direction LT (indicating the axial direction or the height direction) of the suction hand 20. The opening of the intake passage 33 leading to the outside of the shell 31 is the intake port 33a. The opening of the exhaust passage 34 leading to the outside of the shell 31 is the exhaust port 34a. The exhaust port 34a is formed in a conical shape (conical shape) that expands from the inside of the shell 31 toward the outside.

[0044] The first rotating axis 41a of the first rotor 41 and the second rotating axis 42a of the second rotor 42 are arranged on a plane perpendicular to the straight line C. That is, when observing the suction hand 20 from the side, the straight line C (equivalent to the length direction LT of the suction hand 20) is perpendicular to the rotating axes 41a and 42a. The first rotating axis 41a is parallel to the second rotating axis 42a. The rotors 41 and 42 are formed of metal or the like and are two-blade rotors having mountain teeth and valley teeth that mesh with each other. The rotors 41 and 42 rotate, thereby sucking air from the air intake port 33a and exhausting air from the exhaust port 34a. The rotors 41 and 42 rotate, for example, at 4000 rpm. The rotors 41 and 42 (vacuum pumps 30) intermittently suck air from the air intake port 33a and intermittently exhaust air from the exhaust port 34a.

[0045] The motor 45 (electric motor) is, for example, a DC motor driven by DC power. The output shaft 46 of the motor 45 is perpendicular to the straight line C. The output shaft 46 of the motor 45 is parallel to the rotating shafts 41a and 42a. The motor 45 is arranged on the side opposite to the suction cup portion 70 relative to the housing 31. A predetermined gap is formed between the motor 45 and the housing 31.

[0046] like Figure 3 As shown, relative to the motor 45 and the housing 31, in the axial direction of the output shaft 46 of the motor 45 ( Figure 3 One side ( Figure 3 In other words, the motor 45 and the housing 31 are arranged on the same side with respect to the gear mechanism 50.

[0047] The gear mechanism 50 (transmission mechanism) transmits the rotational force of the motor 45 to the rotors 41 and 42. Figure 4 As shown, the gear mechanism 50 includes gears 51 to 54 and an intermediate shaft 55. An output gear 51 is mounted on the output shaft 46 of the motor 45. The intermediate shaft 55 is parallel to the output shaft 46 and the rotating shafts 41a and 42a. An intermediate gear 52 is mounted on the intermediate shaft 55. The output gear 51 and the intermediate gear 52 mesh with each other. A first gear 53 is mounted on the first rotating shaft 41a of the first rotor 41. The intermediate gear 52 and the first gear 53 mesh with each other. A second gear 54 is mounted on the second rotating shaft 42a of the second rotor 42. The first gear 53 and the second gear 54 mesh with each other.

[0048] The rotational force of the output shaft 46 of the motor 45 is transmitted to the first rotating shaft 41a of the first rotor 41 via the output gear 51, the intermediate gear 52, and the first gear 53. As a result, the first rotor 41 is rotated. In addition, the rotational force of the output shaft 46 of the motor 45 is transmitted to the second rotating shaft 42a of the second rotor 42 via the output gear 51, the intermediate gear 52, the first gear 53, and the second gear 54. As a result, the second rotor 42 is rotated. The first rotor 41 and the second rotor 42 rotate in opposite directions at equal rotation speeds.

[0049] like Figure 2 , Figure 3 As shown, a head 60 is arranged on the side opposite to the motor 45 relative to the shell 31. The head 60 is formed of metal or the like into a cylindrical shape having a flange portion 60a. A suction passage 61 extending in the direction of a straight line C (corresponding to the length direction LT of the suction hand 20) is formed inside the head 60. The suction passage 61 is formed in a straight line. Therefore, the suction passage 61, the air intake port 33a, and the air exhaust port 34a are arranged on the same straight line C. A suction cup portion 70 is installed at the top end of the head 60 (the end on the side opposite to the shell 31). That is, the suction cup portion 70 is arranged at the top end in the length direction LT of the suction hand 20. Moreover, the suction cup portion 70, the suction passage 61, the shell 31, and the motor 45 are arranged in the order of the suction cup portion 70, the suction passage 61, the shell 31, and the motor 45 in the direction of the straight line C.

[0050] The suction cup portion 70 (adsorption portion) is formed into a disc shape by rubber or the like. A through hole 71 is formed in the suction cup portion 70. The through hole 71 penetrates the suction cup portion 70 in the direction of the straight line C. The air intake port 33a of the housing 31 is connected to the through hole 71 via the suction passage 61. Therefore, when air is sucked from the air intake port 33a, the air is sucked from the through hole 71 of the suction cup portion 70. As a result, the interior of the suction cup portion 70 becomes a negative pressure, and the workpiece W is adsorbed by the suction cup portion 70.

[0051] The substrate 73 includes a power supply circuit for supplying power to the motor 45, a control circuit for controlling the driving of the motor 45, and the like. The substrate 73 is connected to a cable (not shown) of the arm 10A via a connector 76. The control unit 86 supplies power to the substrate 73 via the cable and sends a signal. The substrate 73 controls the driving of the motor 45 based on the signal received from the control unit 86. Thus, the action of the suction hand 20 is controlled.

[0052] The suction hand 20 includes a housing 78 . The vacuum pump 30 and the substrate 73 are accommodated in the housing 78 .

[0053] In the above structure, the vacuum pump 30 is miniaturized in order to be built into the suction hand 20. Therefore, the motor 45 that drives the rotors 41 and 42 of the vacuum pump 30 is also miniaturized. In the case where the motor 45 is small, the load of the motor 45 driving the rotors 41 and 42 becomes high, and the temperature of the motor 45 and even the temperature of the suction hand 20 may increase excessively.

[0054] Therefore, in the present embodiment, the motor 45 is arranged at a position opposite to the exhaust port 34a of the housing 31. In other words, the motor 45 is arranged on an extension line (straight line C) of the exhaust passage 34 extending from the inside of the housing 31 to the exhaust port 34a. Therefore, the air exhausted from the exhaust port 34a is blown to the motor 45, and the motor 45 is air-cooled.

[0055] However, if the size of the exhaust port 34a is small relative to the size of the motor 45, the air exhausted from the exhaust port 34a may only reach a very small part of the motor 45. In this case, the effect of air cooling the motor 45 by exhausting air may be reduced.

[0056] In view of this, the exhaust port 34a is formed in a conical shape (tapered shape) that expands from the inside toward the outside of the housing 31. Therefore, the air exhausted from the exhaust port 34a flows toward the motor 45 while expanding.

[0057] In addition, in the housing 31, the air inlet 33a opens in the direction of the suction cup portion 70 in the direction of the straight line C, and the air outlet 34a opens in the direction opposite to the suction cup portion 70. The rotating shafts 41a and 42a of the rotors 41 and 42 are perpendicular to the direction of the straight line C (arranged on a plane perpendicular to the straight line C). Here, if one of the rotating shafts 41a and 42a of the rotors 41 and 42 is integrated with the output shaft 46 of the motor 45 in order to simplify the structure of the suction hand 20, the motor 45 will be arranged in the axial direction of the rotating shafts 41a and 42a relative to the housing 31. In this case, the motor 45 cannot be arranged at a position opposite to the exhaust port 34a.

[0058] In view of this, the output shaft 46 of the motor 45 is parallel to the rotation axes 41a and 42a of the rotors 41 and 42, and the gear mechanism 50 is arranged on one side of the axial direction of the output shaft 46 relative to the motor 45 and the housing 31. Therefore, the rotational force of the motor 45 is transmitted to the rotors 41 and 42 via the gear mechanism 50.

[0059] In addition, when the state in which the workpiece W is not sucked by the suction cup part 70 of the suction hand 20 is transferred to the state in which the workpiece W is sucked by the suction cup part 70, the air sucked from the air intake port 33a and the air discharged from the exhaust port 34a gradually decrease. However, the suction cup part 70 and the workpiece W are not completely in close contact, and a gap is slightly formed between the suction cup part 70 and the workpiece W. Therefore, air is sucked from the gap and the air is continuously discharged from the exhaust port 34a. In addition, at the exhaust port 34a, a reverse flow of air is generated due to the pressure difference of the air. Therefore, the reverse flow of air is discharged from the exhaust port 34a again, and the air is continuously discharged from the exhaust port 34a. Therefore, even in the state in which the workpiece W is sucked by the suction hand 20, the motor 45 can be air-cooled. In addition, if the motor 45 is stopped when the workpiece W is not sucked by the suction hand 20, the air is stopped from being discharged from the exhaust port 34a. However, at this time, since the heat generation of the motor 45 is also stopped, the excessive rise in the temperature of the motor 45 can be suppressed.

[0060] In addition, the vacuum pump 30 intermittently sucks air from the air intake port 33a and intermittently discharges air from the air exhaust port 34a. Due to the pressure difference of air generated when the vacuum pump 30 intermittently sucks air from the air intake port 33a, a pulsation sound is generated at the air intake port 33a. In addition, due to the pressure difference of air generated when the vacuum pump 30 intermittently discharges air from the air exhaust port 34a, a pulsation sound that is louder than the pulsation sound generated at the air intake port 33a is generated at the air exhaust port 34a. In addition, during one rotation of the first rotating shaft 41a of the first rotor 41, a pulsation sound of the number of rotors (2) × the number of rotor blades (2) = 4 times is generated at the air exhaust port 34a. Since there is also a situation where the robot 10 and the user (person) cooperate and work close to each other, it is desirable to suppress the noise generated by the suction hand 20.

[0061] Therefore, in the present embodiment, the exhaust port 34a is covered by the first component 48. That is, the first component 48 covers the opening (part) in the vacuum pump 30 where the pulsation sound is generated. The first component 48 is formed of a sintered material (porous material) of stainless steel. Therefore, even if the exhaust port 34a and the motor 45 are opposed to each other with the first component 48 in between, the air exhausted from the exhaust port 34a will pass through the first component 48 and blow to the motor 45. That is, even if the motor 45 and the exhaust port 34a are opposed to each other with the air-permeable first component 48 or the first component 48 having a passage for air to pass through, the motor 45 can be air-cooled.

[0062] The first member 48 is formed in a plate shape having the same shape as the surface 31a (predetermined surface) on which the exhaust port 34a is formed in the housing 31, and is attached to the surface 31a. Specifically, the first member 48 is formed in a rectangular plate shape having a desired thickness and is fixed by bolts 48a (see Figure 3 ) is fixed to the housing 31. Thus, the first component 48 is in close contact with the surface 31a.

[0063] Furthermore, when the vacuum pump 30 is driven, air is exhausted from the exhaust port 34a via the first member 48. Figure 5 As shown, the air exhausted from the exhaust port 34a passes through the fine gap formed inside the sintered material when passing through the first member 48. As a result, the pressure difference of the air is reduced, and the pulsation sound (noise) generated at the exhaust port 34a is suppressed.

[0064] As described above, pulsation sound is also generated at the air intake port 33a due to the pressure difference of air generated when the vacuum pump 30 intermittently sucks air from the air intake port 33a.

[0065] Therefore, in this embodiment, the air inlet 33a is covered by the second component 49. Specifically, the second component 49 covers the air inlet 33a via a space 61a formed as a part of the suction passage 61 inside the head 60. That is, the second component 49 covers the opening (part) where the pulsation sound is generated in the vacuum pump 30. The second component 49 is formed of a sintered material (porous material) of stainless steel. The second component 49 is formed in a circular plate shape having a desired thickness.

[0066] When the vacuum pump 30 is driven, air is sucked from the air inlet 33a via the second member 49 and the space 61a. Figure 5 Similarly, the air sucked from the air inlet 33a passes through the fine gap formed inside the sintered material when passing through the second member 49. As a result, the pressure difference of the air is reduced, and the pulsation sound (noise) generated at the air inlet 33a is suppressed.

[0067] Figure 6 48 and the second component 49. In the first comparative example which is the same as the present embodiment except that the first component 48 and the second component 49 are not provided, the noise is about 77 dB. In the second comparative example which is the same as the present embodiment except that the first component 48 is not provided, the noise is about 76 dB. That is, the second component 49 has the effect of suppressing about 1 dB of noise. In the present embodiment, the noise is about 65 dB. That is, the first component 48 and the second component 49 have the effect of suppressing about 12 dB of noise.

[0068] Figure 7 This is a graph showing the relationship between the size of the internal pores (nominal filtration accuracy (also referred to as "absolute filtration accuracy" or "nominal filtration accuracy")) of the porous material forming the second component 49 disposed at the air inlet 33a and the size of the noise generated from the second component 49. Figure 7As shown in FIG. 1 , the noise generated when the second member 49 formed of a porous material is present at the air inlet 33a as in the present embodiment is smaller than the noise generated when the second member 49 is not present at the air inlet 33a. That is, Figure 7 FIG. 4 shows that the noise suppression effect can be exerted when the second member 49 formed of a porous material is present at the air inlet 33a as in this embodiment. Figure 7 As shown, the smaller the nominal filtering accuracy of the second component 49 is, the greater the noise suppression effect is. Figure 7 As shown, the noise reduction effect is particularly great when the nominal filtration accuracy is 40 μm or less.

[0069] In addition, in this embodiment, the nominal filtration accuracy of the first component 48 disposed at the exhaust port 34a may be different from the nominal filtration accuracy of the second component 49 disposed at the air intake port 33a. Specifically, it may be configured such that the nominal filtration accuracy of the second component 49 disposed at the air intake port 33a is 100 μm, and the nominal filtration accuracy of the first component 48 disposed at the exhaust port 34a is 20 μm, and the nominal filtration accuracy of the second component 49 is greater than the nominal filtration accuracy of the first component 48. This is because Figure 7 It can be seen that even if the nominal filtration accuracy is 100μm, the noise suppression effect can be fully exerted, and because the nominal filtration accuracy is 100μm, the air intake port 33a covered by the second component 49 exerts sufficient attraction, that is, to ensure that the suction hand 20 can adsorb the workpiece W. In addition, generally, the larger the nominal filtration accuracy of the porous material, the lower the cost. Therefore, by using a porous material with a large nominal filtration accuracy in the second component 49, the effect of reducing the manufacturing cost of the suction hand 20 is also exerted. On the other hand, the first component 48 arranged at the exhaust port 34a is formed of a porous material with a small nominal filtration accuracy, so that the noise suppression effect can be increased.

[0070] Figure 8 4 is a diagram showing the relationship between the thickness of the sintered material forming the first component 48 and the second component 49 and the silencing effect (noise suppression effect). Figure 8 As shown in Figure 2, the greater the thickness of the sintered material, the greater the noise suppression effect. Figure 8 As shown in FIG. 1 , the greater the thickness of the sintered material, the greater the noise suppression effect. In this embodiment, even if the thickness of the sintered material is 3 mm or less, a sufficient noise suppression effect can be exerted. In this way, even if the thickness of the sintered material used in the first component 48 and the second component 49 is thin, the noise suppression effect can be exerted, so the structure for suppressing noise can be simplified, and the vacuum pump 30 can be miniaturized.

[0071] The present embodiment described in detail above has the following advantages.

[0072] The suction hand 20 has a built-in vacuum pump 30. Therefore, there is no need to connect the vacuum pump 30 and the suction hand 20 with a pipe, which can prevent the pipe from being entangled in the robot 10 when the robot 10 moves. The vacuum pump 30 is a Roots pump, so it has a simple structure and can be easily miniaturized.

[0073] The motor 45 is arranged at a position opposite to the exhaust port 34a. In other words, the motor 45 is arranged on an extension line of the exhaust passage 34 extending from the inside of the housing 31 to the exhaust port 34a. Therefore, the air exhausted from the exhaust port 34a can be blown to the motor 45, and the motor 45 can be air-cooled. Therefore, even if the motor 45 is miniaturized and the load of the motor 45 increases, the temperature of the motor 45 can be suppressed from excessively rising, and the temperature of the suction hand 20 can be suppressed from excessively rising.

[0074] The exhaust port 34a is formed into a cone shape that expands from the inside toward the outside of the housing 31. According to such a structure, the range in which the air discharged from the exhaust port 34a flows can be expanded. Therefore, the range in which the air blows to the motor 45 can be expanded, and the effect of air cooling the motor 45 by the air can be improved.

[0075] The suction cup part 70 is arranged at the top of the length direction LT (hereinafter referred to as the "length direction") of the suction hand 20. Therefore, by controlling the robot 10 in such a manner that the length direction LT of the suction hand 20 is directed toward the workpiece W, the workpiece W can be sucked by the suction cup part 70 arranged at the top of the length direction. The air suction port 33a opens in the direction of the suction cup part 70 in the length direction LT. Therefore, the air suction port 33a and the suction cup part 70 can be connected by a linear suction passage 61, and the structure of the suction hand 20 can be simplified.

[0076] The output shaft 46 of the motor 45 is parallel to the rotation shafts 41a and 42a of the rotors 41 and 42, and the gear mechanism 50 is arranged on one side of the axial direction of the output shaft 46 relative to the motor 45 and the housing 31. Therefore, even if one of the rotation shafts 41a and 42a of the rotors 41 and 42 is not integral with the output shaft 46 of the motor 45, the rotational force of the motor 45 can be transmitted to the rotors 41 and 42. Furthermore, the suction cup portion 70, the suction passage 61, the housing 31, and the motor 45 are arranged in the order of the length direction LT. Therefore, in the length direction LT, the motor 45 can be arranged in the direction opposite to the suction cup portion 70 relative to the housing 31, that is, in the direction of the opening of the exhaust port 34a. Therefore, the structure of the suction hand 20 can be simplified, and a structure in which the motor 45 is air-cooled by the air discharged from the exhaust port 34a can be realized.

[0077] The suction passage 61 is formed in a straight line. Moreover, the suction passage 61, the air intake port 33a, and the exhaust port 34a are arranged on the same straight line C. Therefore, the distance from the suction cup portion 70 to the exhaust port 34a can be set to the shortest, and the exhaust efficiency of the vacuum pump 30 can be improved. Furthermore, since the efficiency of conveying air from the suction cup portion 70 to the exhaust port 34a can be improved, the effect of air cooling the motor 45 by exhaust can be improved.

[0078] The first component 48 formed of a porous material covers the exhaust port 34a, so the air is exhausted from the exhaust port 34a through the first component 48. The air exhausted from the exhaust port 34a passes through the fine gap formed inside the porous material when passing through the first component 48. As a result, the pressure difference of the air becomes smaller, and the pulsation sound (noise) generated at the exhaust port 34a can be suppressed. Furthermore, since only the first component 48 formed of a porous material is used to cover the exhaust port 34a, the structure for suppressing noise can be simplified, and the vacuum pump 30 can be miniaturized.

[0079] The first member 48 is formed of a sintered stainless steel material. According to such a structure, the first member 48 can be manufactured at a low cost compared to a so-called muffler of the vacuum pump 30, and the durability of the first member 48 can be improved.

[0080] The second member 49 formed of a porous material covers the air inlet 33a. Therefore, the pulsation sound (noise) generated at the air inlet 33a can be suppressed, and the noise generated by the suction hand 20 can be further suppressed.

[0081] The second member 49 is formed of a sintered stainless steel material. According to such a structure, the second member 49 can be manufactured at a low cost compared to a so-called muffler of the vacuum pump 30, and the durability of the second member 49 can be improved.

[0082] The exhaust port 34a is formed in a tapered shape that expands from the inside to the outside of the housing 31. Therefore, the pressure difference between the air in the exhaust port 34a and the air outside the exhaust port 34a can be reduced, and the pulsation sound (noise) generated in the exhaust port 34a can be suppressed.

[0083] The first member 48 is formed in a plate shape having the same shape as the surface 31a of the housing 31 where the exhaust port 34a is formed, and is attached to the surface 31a. With this structure, the first member 48 can be easily sized and attached to the surface 31a of the housing 31.

[0084] In addition, the above-mentioned embodiment may be implemented by changing the following: The same reference numerals are attached to the same parts as those in the above-mentioned embodiment, and the description thereof is omitted.

[0085] The shape of the suction passage 61 is not limited to a straight line, and may be a curved line or a shape having a curved portion.

[0086] Instead of the suction cup portion 70, a sponge-type suction hand (suction portion) equipped with a sponge may be used. In this case, air is sucked from the sponge even when the workpiece W is adsorbed, so that air can continue to be discharged from the exhaust port 34a, and the motor 45 can be air-cooled. In addition, a valve or the like can be provided in the head portion 60 for introducing air into the suction passage 61 to maintain the pressure at a specified pressure when the pressure in the suction passage 61 is lower than a specified pressure. A small hole can also be provided in the head portion 60 for introducing a small amount of air into the suction passage 61. Even with these structures, air can continue to be discharged from the exhaust port 34a when the workpiece W is adsorbed, and the motor 45 can be air-cooled.

[0087] The exhaust hole 34a is not limited to a tapered shape, and may be formed in a cylindrical shape extending in the axial direction with the same diameter.

[0088] It is also possible to change the shape of the gears of the gear mechanism 50 and adopt a structure in which the output shaft 46 of the motor 45 and the rotating shafts 41 a and 42 a of the rotors 41 and 42 are not parallel.

[0089] The transmission mechanism for transmitting the rotational force of the motor 45 to the rotors 41 and 42 is not limited to the gear mechanism 50 , and a structure in which the rotational force is transmitted using a pulley or a belt may be employed.

[0090] The first member 48 may be shaped so as to cover only the vicinity of the exhaust port 34a. Alternatively, the first member 48 may not cover the exhaust port 34a but may be disposed inside the exhaust port 34a.

[0091] The first component 48 and the second component 49 are not limited to sintered materials of stainless steel, but may be sintered materials of other metals. In addition, the first component 48 and the second component 49 are not limited to sintered materials, but may be porous materials formed of ceramics or resins. Even in this case, the same Figure 5 Same effect.

[0092] The second member 49 may be omitted. Even in this case, the first member 48 can suppress the noise generated at the exhaust port 34a, which is louder than the noise generated at the intake port 33a.

[0093] The vacuum pump 30 is not limited to a Roots pump, and a claw pump or a vortex pump as a positive displacement rotary pump may also be used. Even in this case, the air continuously discharged from the exhaust port 34a of the housing 31 can be blown to the motor 45 to air-cool the motor 45. In addition, even if it is a diaphragm pump or a piston pump that does not continuously discharge air from the exhaust port 34a of the housing 31 as a vacuum pump having a check valve or the like, as long as the vacuum pump intermittently sucks air from the air intake port 33a and intermittently discharges air from the exhaust port 34a, the effect of suppressing noise can be obtained by the first component 48 and the second component 49.

[0094] The robot 10 is not limited to a vertical articulated robot, but may be a horizontal articulated robot or the like.

[0095] Furthermore, the suction mechanism of the present invention can be mounted on other than industrial robots, for example, a humanoid robot, or on various industrial equipment other than robots that require suction work.

Claims

1. A suction hand, mounted on an industrial robot used as a device, which is a suction hand of the industrial robot that sucks a workpiece through a suction part, wherein: A vacuum pump is built in, the vacuum pump having a housing formed with an air intake port and an air exhaust port, and air is sucked from the air intake port and discharged from the air exhaust port. The adsorption portion is connected to the air inlet via a suction passage. A first member formed of a porous material covers the exhaust port. A second member formed of a porous material covers the air inlet. The size of the internal pores of the first member formed of the porous material is smaller than the size of the internal pores of the second member formed of the porous material.

2. The suction hand according to claim 1, wherein: The first component is formed of a sintered material of stainless steel.

3. The suction hand according to claim 2, wherein: The second member is formed of a sintered material of stainless steel.

4. The suction hand according to any one of claims 1 to 3, wherein: The exhaust port is formed in a tapered shape that expands from the inside toward the outside of the housing.

5. The suction hand according to any one of claims 1 to 3, wherein: The first member is formed in a plate shape having the same shape as a predetermined surface of the housing on which the exhaust port is formed, and is attached to the predetermined surface.

6. The suction hand according to any one of claims 1 to 3, wherein: The suction passage is formed in a straight line. The suction passage, the air intake port, and the air exhaust port are arranged on the same straight line.

7. The suction hand according to any one of claims 1 to 3, wherein: The vacuum pump is a Roots pump.

8. The suction hand according to any one of claims 1 to 3, wherein: The target device is an industrial robot having the suction hand.

9. An industrial robot, characterized in that: The device is provided with a suction hand, and the suction hand has: A suction part for sucking a workpiece; a housing having an air intake port and an air exhaust port; and A vacuum pump, which is built into the housing and sucks air from the air inlet and discharges air from the air outlet; The adsorption portion is connected to the air inlet via a suction passage. A first member formed of a porous material covers the exhaust port. A second member formed of a porous material covers the air inlet. The size of the internal pores of the first member formed of the porous material is smaller than the size of the internal pores of the second member formed of the porous material.

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