Pressure-adjustable floating Z-axis device

Abstract

The present invention discloses a floating Z-axis device with adjustable pressure, which includes an R-axis mechanism and a Z-axis. An axis cavity corresponding to the Z-axis is provided inside the R-axis mechanism. The upper end of the Z-axis is located in the axis cavity. An adsorption air passage is provided inside the Z-axis. Air floating air outlets and adsorption air inlets are provided on the inner wall of the axis cavity. A negative pressure air outlet corresponding to the adsorption air inlet is provided on the Z-axis. A positive pressure air passage and a negative pressure air passage are provided inside the R-axis mechanism. A counterweight motor is provided inside the axis cavity. The counterweight motor includes a stator and a rotor, and the rotor is connected to the Z-axis. An air floating block is correspondingly provided below the R-axis mechanism. An air floating shaft plane is correspondingly provided on the Z-axis. A plurality of throttle holes are provided on one side of the air floating block corresponding to the air floating shaft plane, and the throttle holes communicate with the positive pressure air passage. The present invention realizes the up and down floating buffer when picking up materials downward, prevents the small floating Z-axis from self-rotating, and realizes the adjustment of the external motor pressure on the Z-axis and the monitoring and feedback of the pressure size for picking up products.

Description

Technical Field

[0001] The present invention relates to the field of manipulators, and in particular to a floating Z-axis device with adjustable pressure. Background Art

[0002] Most of the existing devices for picking up materials (such as small chips, etc.) in the downward Z-axis direction adopt a "large Z-axis + R-axis" picking structure member. The Z-axis is fixed on the guide rail, and the R-axis is fixed on the Z-axis. The Z-axis drives the structure member downward through a power source to pick up the product. This method belongs to hard-contact material picking, without a floating buffer function device, which is easy to damage the material when picking up the material. At the same time, there is no monitoring and feedback of pressure, and a pressure closed-loop cannot be achieved. In addition, there is no adjustment function for different pressures, and it cannot meet the requirements of different products for the picking pressure size.

[0003] The existing picking structure method is prone to overshoot of the moving position and damage to the product, or when performing chip die bonding, the solder paste temperature changes instantaneously and expands, resulting in an instantaneous upward thrust of the product on the upper structural member (such as the suction nozzle). Because the current picking structure adopts a hard connection, although some picking structures are equipped with pressure sensors for real-time monitoring of force control to adjust the output size of the motor force, because the chip die bonding time is quite fast, the sensor has not had time to transmit the signal to the motor controller, and this instantaneous large pressure has disappeared, but this force has already exerted too much pressure on the product and damaged the product. At the same time, there are also defects that the size adjustment of different pressures cannot be achieved, and the monitoring and feedback of pressure cannot be achieved. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a floating Z-axis device with adjustable pressure to achieve up and down floating buffering when picking up materials downward and adjustment of the picking pressure.

[0005] To solve the above technical problem, the embodiments of the present invention propose a floating Z-axis device with adjustable pressure, including an R-axis mechanism and a Z-axis. An axis cavity corresponding to the Z-axis is provided inside the R-axis mechanism. The upper end of the Z-axis is located in the axis cavity. An adsorption air passage is provided inside the Z-axis. Air floating air outlet holes and adsorption air inlet holes are provided on the inner wall of the axis cavity. A negative pressure air outlet hole corresponding to the adsorption air inlet hole is provided on the Z-axis. A positive pressure air passage and a negative pressure air passage are provided inside the R-axis mechanism. One end of the adsorption air passage communicates with the negative pressure air outlet hole, and the other end is used to connect to a nozzle. One end of the positive pressure air passage is used to connect to an external positive pressure air source, and the other end communicates with the air floating air outlet hole. One end of the negative pressure air passage is used to connect to an external negative pressure air source, and the other end communicates with the adsorption air inlet hole. A counterweight motor is provided inside the axis cavity. The counterweight motor includes a stator and a rotor, and the rotor is connected to the Z-axis. An air floating block is correspondingly provided below the R-axis mechanism. An air floating shaft plane is correspondingly provided on the Z-axis. A plurality of throttle holes are provided on one side of the air floating block corresponding to the air floating shaft plane, and the throttle holes communicate with the positive pressure air passage.

[0006] Furthermore, there are 2 groups of air flotation blocks, which are symmetrically arranged with respect to the Z-axis, and 2 groups of air flotation axis planes are correspondingly arranged on the Z-axis.

[0007] Furthermore, the outer diameter of the upper end of the Z-axis is greater than that of the lower end, the air flotation axis plane is recessed in the lower end, and the up and down movement of the Z-axis is limited by the air flotation block.

[0008] Furthermore, the stator is composed of a coil and a bobbin, and the rotor is composed of a magnet and a yoke.

[0009] Furthermore, the yoke is arranged on the top of the magnet, and the magnet is connected to the Z-axis.

[0010] Furthermore, a rubber ring is arranged on the outer periphery of the bobbin, and the stator is arranged in the shaft cavity by interference fit.

[0011] Furthermore, there are multiple air flotation air outlets, and the multiple air flotation air outlets are evenly distributed around the inner wall of the shaft cavity.

[0012] Furthermore, the multiple air flotation air outlets are divided into multiple rows up and down, and each row of air flotation air outlets is evenly distributed around the inner wall of the shaft cavity.

[0013] Furthermore, a displacement sensor for detecting the displacement of the Z-axis is arranged on the R-axis mechanism.

[0014] The beneficial effects of the present invention are as follows: The present invention realizes the up and down floating buffer when picking up materials downward, and at the same time prevents the floating Z-axis from self-rotating, but can still rotate with the rotating motor (R-axis motor); the present invention realizes the adjustment of the external motor pressure on the Z-axis and the monitoring and feedback of the pressure magnitude for picking up products, and at the same time avoids the blind area where it is impossible to judge whether the suction nozzle on the Z-axis touches the product. When the product is under pressure, the current change value of the counterweight motor is monitored, and then the signal is fed back to the large Z-axis motor to stop or continue the displacement movement of pressing down the product. The present invention can be directly applied to the end of the R-axis of the conventional ZR-axis, can float up and down, and has no friction with the air flotation block, ensuring that there is only low frictional resistance between the parts and the air film at the end, so as to ensure that during the chip mounting and die bonding process, when the product expands due to heat, it can float up and down, ensuring that the product is not under excessive pressure, and at the same time, the pressure can be adjusted to be compatible with the requirements of different products for the picking pressure magnitude. Description of the Drawings

[0015] Figure 1 is the three-dimensional structure diagram of a floating Z-axis device with adjustable pressure according to an embodiment of the present invention.

[0016] Figure 2 is the partial exploded view of a floating Z-axis device with adjustable pressure according to an embodiment of the present invention.

[0017] Figure 3 is Figure 2 the enlarged view at F in

[0018] Figure 4 It is a three - dimensional structure diagram of an air - floating block according to an embodiment of the present invention.

[0019] Figure 5 It is a bottom view of a floating Z - axis device with adjustable pressure according to an embodiment of the present invention.

[0020] Figure 6 is Figure 5 The cross - sectional view at C - C in

[0021] Figure 7 It is a bottom view of the floating Z - axis device with the air - floating block hidden according to an embodiment of the present invention.

[0022] Figure 8 is Figure 7 The cross - sectional view at D - D in

[0023] Figure 9 is Figure 7 The cross - sectional view at H - H in

[0024] Figure 10 It is a bottom view of a floating Z - axis device with adjustable pressure according to another embodiment of the present invention.

[0025] Figure 11 is Figure 10 The cross - sectional view at E - E in

[0026] Figure 12 It is a three - dimensional structure diagram of a counterweight motor according to another embodiment of the present invention.

[0027] Explanation of the reference numerals in the drawings

[0028] R - axis mechanism 1, Z - axis 2, adsorption air passage 3, air - floating air outlet hole 4, adsorption air inlet hole 5, negative - pressure air outlet hole 6, positive - pressure air passage 7, negative - pressure air passage 8, air - floating block 9, throttle hole 10, air - floating shaft plane 11, exhaust cavity 12, exhaust hole 13, inner snap ring 14,

[0029] Counterweight motor 20, coil 21, wire holder 22, magnet 23, magnetic yoke 24, rubber ring 25. Detailed implementation manners

[0030] It should be noted that, without conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0031] In the embodiments of the present invention, if there are directional indications (such as up, down, left, right, front, back...), they are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture (as shown in the attached drawings). If this specific posture changes, the directional indications will also change accordingly.

[0032] In addition, in the present invention, the descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0033] Please refer to Figures 1 to 12 , the pressure-adjustable floating Z-axis device in the embodiments of the present invention includes an R-axis mechanism and a Z-axis. The R-axis mechanism is composed of a rotating R-axis and a shunt base.

[0034] An axial cavity corresponding to the Z-axis is provided inside the R-axis mechanism, and the axial cavity is cylindrical. The upper end of the Z-axis is located in the axial cavity. An adsorption air passage is provided inside the Z-axis, and air floating air outlets and adsorption air inlets are provided on the inner wall of the axial cavity. A gap is left between the Z-axis and the axial cavity, and the gas blown out from the air floating air outlets diffuses up and down to form an air film. Preferably, an inner snap ring is provided at the bottom of the R-axis mechanism, and the inner snap ring can be used to limit the up and down movement of the Z-axis.

[0035] An exhaust cavity can be provided on the inner wall of the axial cavity, and an exhaust hole communicating with the exhaust cavity is provided on the R-axis mechanism, and exhaust is carried out through the exhaust hole. Gas is blown out from the air floating air outlets, so that an air film is formed between the Z-axis and the inner wall of the axial cavity, thereby reducing the friction force when the Z-axis moves up and down. A negative pressure air outlet corresponding to the adsorption air inlet is provided on the Z-axis, and a positive pressure air passage and a negative pressure air passage are provided inside the R-axis mechanism. One end of the adsorption air passage communicates with the negative pressure air outlet, and the other end is used to connect to a nozzle. One end of the positive pressure air passage is provided with a connector for connecting to an external positive pressure air source, and the other end communicates with the air floating air outlets. One end of the negative pressure air passage is provided with a connector for connecting to an external negative pressure air source, and the other end communicates with the adsorption air inlets. The external negative pressure air source is connected to the suction nozzle through the negative pressure air passage and the adsorption air passage, and the suction nozzle adsorbs and grabs materials.

[0036] A counterweight motor is provided inside the axial cavity. The counterweight motor includes a stator and a rotor, and the rotor is connected to the Z-axis. The present invention dynamically adjusts the counterweight through the electromagnetic force of the counterweight motor to balance the load of the Z-axis.

[0037] In addition to the floating Z-axis of the present invention being able to achieve the up and down floating buffer of the force when picking up materials downward, according to different magnitudes of the force required by the product, different pressures can be adjusted for the floating Z-axis, either pressurized or depressurized, by the thrust of the counterweight motor, and at the same time, the pressure value can be monitored.

[0038] A pneumatic floating block is correspondingly provided below the R-axis mechanism, a pneumatic floating shaft plane is correspondingly provided on the Z-axis, and 2n throttle holes (preferably, there are 2 throttle holes on one pneumatic floating block) are provided on one side of the pneumatic floating block corresponding to the pneumatic floating shaft plane. The throttle holes communicate with the positive pressure air duct, and the 2n throttle holes are symmetrically distributed on the left and right sides of the Z-axis axis, where n is a positive integer. In specific implementation, a number of tiny throttle holes can also be provided on one side surface of the pneumatic floating block corresponding to the pneumatic floating shaft plane, and the air flow blown out from the number of tiny throttle holes forms a whole-surface air flow blowing towards the pneumatic floating shaft plane, applying pressure to the whole surface of the pneumatic floating shaft plane (that is, the air flow pressures applied to both sides of the pneumatic floating shaft plane along the axis are equal), to prevent the Z-axis from deflecting.

[0039] Preferably, there are 2 groups of pneumatic floating blocks, symmetrically arranged relative to the Z-axis, and 2 groups of pneumatic floating shaft planes are correspondingly provided on the Z-axis. The positive pressure air duct between the pneumatic floating block and the R-axis mechanism is sealed by a sealing ring.

[0040] The Z-axis of the present invention can perform up-and-down linear motion and rotational motion within the shaft cavity. In the embodiment of the present invention, only up-and-down linear motion is required. Therefore, in order to prevent the Z-axis from performing rotational motion, pneumatic floating blocks are installed on the left and right sides at the bottom of the R-axis mechanism. A pneumatic floating film is formed by the two small throttle holes on the left and right pneumatic floating blocks and the pneumatic floating shaft plane on the Z-axis. While preventing the Z-axis from rotating, it can also make the Z-axis float upward when subjected to an axial force.

[0041] As an implementation manner, the outer diameter of the upper end of the Z-axis is larger than the outer diameter of the lower end, and the pneumatic floating shaft plane is recessed on the lower end. The up-and-down motion of the Z-axis is limited by the pneumatic floating blocks, that is, the distance between the two pneumatic floating blocks matches the distance between the two pneumatic floating shaft planes on the Z-axis. When the Z-axis moves downward, the upper end of the Z-axis is limited by the pneumatic floating block; when the Z-axis moves upward, the lower end of the Z-axis (at the bottom of the pneumatic floating shaft plane) is limited by the pneumatic floating block.

[0042] As an implementation manner, the stator is composed of a coil and a bobbin, and the rotor is composed of a magnet and a yoke. The yoke is provided on top of the magnet, and the magnet is connected to the Z-axis. A number of rubber rings are provided on the outer periphery of the bobbin. The stator is installed in the shaft cavity through an interference fit between the rubber rings and the shaft cavity (that is, the frictional force generated by the rubber deformation of the rubber rings and the extrusion between the inner wall of the shaft cavity fixes the entire stator of the counterweight motor in the shaft cavity), which is convenient for later replacement of the counterweight motor.

[0043] As an implementation manner, there are multiple pneumatic floating air outlets, and the multiple pneumatic floating air outlets are evenly distributed around the inner wall of the shaft cavity. Preferably, the multiple pneumatic floating air outlets are divided into multiple rows up and down, and each row of pneumatic floating air outlets is evenly distributed around the inner wall of the shaft cavity.

[0044] As an implementation manner, a displacement sensor for detecting the displacement of the Z-axis is provided on the R-axis mechanism. After the Z-axis contacts the product, there is an upward displacement fluctuation. By detecting this displacement change, the change signal is transmitted to the controller of the large Z-axis to perform the next action, avoiding the situation that the floating Z-axis cannot contact the suction nozzle of the thin product or the product at a lower position when the large Z-axis moves down to the same height due to the different thicknesses of the products, resulting in an abnormal vacuum alarm for sucking the product.

[0045] The present invention can be directly applied to the end of the existing rotary R-axis picking structure. The rotary R-axis is fixed on the large Z-axis and moves up and down with the large Z-axis. The present invention is fixed at the end of the picking structure and moves with the rotary R-axis. Since the present invention adopts the air-floating bearing method, there is no mutual contact between the outer circle of the Z-axis of the present invention and the shaft cavity of the R-axis mechanism, and they are separated by an air film. Generally, the air film thickness is between 0.005 and 0.01 mm. In this way, the Z-axis of the present invention is in a floating state. When subjected to an upward pressure exceeding the rated value, it will automatically float upward and will not apply an extrusion force to the underlying material due to size changes, squeezing the product and causing product damage. If it is necessary to increase the pressure on the floating Z-axis, a thrust is applied downward by controlling the counterweight motor; if it is necessary to reduce the pressure on the floating Z-axis, that is, when it is necessary to reduce the weight of the floating Z-axis and the suction nozzle device pressing on the product, a pulling force is applied upward by controlling the counterweight motor to balance part of the gravity of the floating Z-axis and the suction nozzle.

[0046] The present invention adopts a round rod and round hole structure. Therefore, in addition to being able to freely float up and down, the air-floating shaft can also perform self-rotation at any position of 360° when subjected to a radial force. Since the Z-axis of the present invention is to rotate with the R-axis motor to adjust the angular position of the picked material, if the Z-axis of the present invention does not have an anti-rotation device, then the rotational accuracy adjustment of the product in addition to picking buffering cannot be achieved. Therefore, it is necessary to provide an anti-rotation structure for the Z-axis of the present invention, and this structure cannot affect the free up and down floating of the Z-axis of the present invention, that is, there cannot be an external force affecting the frictional resistance of the free up and down floating of the Z-axis of the present invention, otherwise the force control accuracy will be reduced. Therefore, a non-contact anti-rotation of the Z-axis is required. The present invention adopts a principle similar to that of an air-floating bearing. Two planes (i.e., air-floating shaft planes) are provided on both sides of the Z-axis, and then two air-floating blocks are provided on both sides of the two planes. The small holes on the air-floating blocks are throttled and respectively face the planes of the small Z-axis. The air source of the air-floating blocks is connected to an external positive pressure air source through the positive pressure air duct of the R-axis mechanism. The distance between the two air-floating blocks and the air-floating shaft planes of the Z-axis is adjusted to be between 0.005 and 0.01 mm. Then, through the high-pressure gas blown out by the small holes of the two air-floating blocks, a mutual balancing force is generated between the two planes of the Z-axis and the two air-floating blocks, ensuring that the Z-axis will not rotate. At the same time, the air-floating shaft planes of the Z-axis have a preset length (the preset length is consistent with the up and down movement stroke of the Z-axis) up and down to meet the axial up and down floating.

[0047] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A floating Z-axis device with adjustable pressure, comprising an R-axis mechanism and a Z-axis, characterized in that, The R-axis mechanism is provided with a shaft cavity corresponding to the Z-axis. The upper end of the Z-axis is located in the shaft cavity. The Z-axis is provided with an adsorption air passage. The inner wall of the shaft cavity is provided with air flotation air outlets and adsorption air inlets. The Z-axis is provided with negative pressure air outlets corresponding to the adsorption air inlets. The R-axis mechanism is provided with a positive pressure air passage and a negative pressure air passage; one end of the adsorption air passage communicates with the negative pressure air outlet, and the other end is used to connect to a nozzle; one end of the positive pressure air passage is used to connect to an external positive pressure air source, and the other end communicates with the air flotation air outlets; one end of the negative pressure air passage is used to connect to an external negative pressure air source, and the other end communicates with the adsorption air inlets; a counterweight motor is arranged in the shaft cavity. The counterweight motor includes a stator and a rotor, and the rotor is connected to the Z-axis; a air flotation block is correspondingly arranged below the R-axis mechanism. A air flotation shaft plane is correspondingly arranged on the Z-axis. A number of throttle holes are arranged on one side of the air flotation block corresponding to the air flotation shaft plane, and the throttle holes communicate with the positive pressure air passage.

2. The floating Z-axis device with adjustable pressure according to claim 1, wherein There are 2 groups of air flotation blocks, which are symmetrically arranged relative to the Z-axis. 2 groups of air flotation shaft planes are correspondingly arranged on the Z-axis.

3. The floating Z-axis device with adjustable pressure according to claim 1, characterized in that, The outer diameter of the upper end of the Z-axis is larger than that of the lower end. The air flotation shaft plane is recessed in the lower end. The up and down movement of the Z-axis is limited by the air flotation block.

4. The floating Z-axis device with adjustable pressure according to claim 1, characterized in that The stator is composed of a coil and a bobbin, and the rotor is composed of a magnet and a yoke.

5. The floating Z-axis device with adjustable pressure according to claim 4, characterized in that, The yoke is arranged on the top of the magnet, and the magnet is connected to the Z-axis.

6. The floating Z-axis device with adjustable pressure according to claim 4, wherein A rubber ring is arranged on the outer periphery of the bobbin, and the stator is arranged in the shaft cavity by interference fit.

7. The floating Z-axis device with adjustable pressure according to claim 1, wherein There are multiple air flotation air outlets, and the multiple air flotation air outlets are evenly distributed around the inner wall of the shaft cavity.

8. The floating Z-axis device with adjustable pressure according to claim 7, wherein, The multiple air flotation air outlets are divided into multiple rows up and down, and each row of air flotation air outlets is evenly distributed around the inner wall of the shaft cavity.

9. The floating Z-axis device with adjustable pressure according to claim 1, characterized in that, A displacement sensor for detecting the displacement of the Z-axis is arranged on the R-axis mechanism.

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