Floating Z-axis device

Abstract

The present invention discloses a floating Z-axis device, 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. An air floating air outlet hole and an adsorption air inlet hole 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. The present invention realizes the up-and-down floating buffer when picking up materials downward under force, and at the same time prevents the floating small Z-axis from self-rotating, but can still perform rotational movement following the rotation motor.

Description

Technical Field

[0001] The present invention relates to the field of manipulators, and in particular to a floating Z-axis device. 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. The Z-axis is fixed on the guide rail, the R-axis is fixed on the Z-axis, and the Z-axis drives the structure to pick up products downward through a power source. This method belongs to hard-contact material picking and does not have a floating buffer function device, which is likely to damage the materials when picking up materials.

[0003] The existing picking structure is likely to cause overshoot of the moving position and crush the product. Or, when performing chip die bonding, the solder paste expands instantaneously due to temperature change, resulting in an instantaneous upward thrust on the upper structure (such as the suction nozzle) by the product. 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 magnitude of the motor force, since the time for chip die bonding 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. 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 to achieve up and down floating buffering when picking up materials downward.

[0005] To solve the above technical problem, the embodiments of the present invention propose a floating Z-axis device, 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 for connecting to a gas nozzle; one end of the positive pressure air passage is used for connecting to an external positive pressure air source, and the other end communicates with the air floating air outlet holes; one end of the negative pressure air passage is used for connecting to an external negative pressure air source, and the other end communicates with the adsorption air inlet holes.

[0006] Further, an air floating block is correspondingly provided below the R-axis mechanism, an air floating axis plane is correspondingly provided on the Z-axis, and a plurality of throttle holes are provided on one side of the air floating block corresponding to the air floating axis plane, and the throttle holes communicate with the positive pressure air passage.

[0007] Further, there are 2 groups of air floating blocks, which are symmetrically arranged relative to the Z-axis, and 2 groups of air floating axis planes are correspondingly provided on the Z-axis.

[0008] Further, the outer diameter of the upper end of the Z-axis is larger than that of the lower end, the air floating axis plane is recessed on the lower end, and the up and down movement of the Z-axis is limited by the air floating block.

[0009] Further, there are multiple air floating pores, and the multiple air floating pores are evenly distributed on the inner wall of the shaft cavity.

[0010] Further, the multiple air floating pores are divided into multiple rows up and down, and each row of air floating pores is evenly distributed on the inner wall of the shaft cavity.

[0011] Further, a displacement sensor for detecting the displacement of the Z-axis is provided on the R-axis mechanism.

[0012] 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 also follow the rotation motor (R-axis motor) to perform rotational movement; the present invention can be directly applied to the end of the R-axis of a conventional ZR-axis, ensuring that the Z-axis does not rotate randomly, and can also perform up and down floating, without friction with the air floating 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 follow the up and down floating to ensure that the product is not under excessive pressure. Description of the Drawings

[0013] Figure 1 is a three-dimensional structure diagram of the floating Z-axis device according to an embodiment of the present invention.

[0014] Figure 2 is a partial exploded view of the floating Z-axis device according to an embodiment of the present invention.

[0015] Figure 3 is Figure 2 an enlarged view of the F position in

[0016] Figure 4 is a three-dimensional structure diagram of the air floating block according to an embodiment of the present invention.

[0017] Figure 5 is a bottom view of the floating Z-axis device according to an embodiment of the present invention.

[0018] Figure 6 is Figure 5 a cross-sectional view taken along the C-C line in

[0019] Figure 7 is a bottom view of the floating Z-axis device with the air floating block hidden according to an embodiment of the present invention.

[0020] Figure 8 is Figure 7 a cross-sectional view taken along the D-D line in

[0021] Figure 9 is Figure 7 a cross-sectional view taken along the H-H line in

[0022] Description of the Reference Numerals in the Drawings

[0023] R-axis mechanism 1, Z-axis 2, adsorption air duct 3, air floating outlet hole 4, adsorption inlet hole 5, negative pressure outlet hole 6, positive pressure air duct 7, negative pressure air duct 8, air floating block 9, throttle hole 10, air floating shaft plane 11, exhaust cavity 12, exhaust hole 13. Detailed implementation manners

[0024] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0025] 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 specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0026] In addition, in the present invention, the descriptions involving "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0027] Please refer to Figures 1 to 9 , the 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 seat.

[0028] An axis cavity corresponding to the Z-axis is provided inside the R-axis mechanism, and the axis cavity is cylindrical. The upper end of the Z-axis is located in the axis cavity. An adsorption air duct is provided inside the Z-axis, and air floating outlet holes and adsorption inlet holes are provided on the inner wall of the axis cavity. A gap is left between the Z-axis and the axis cavity, and the gas blown out from the air floating outlet holes diffuses up and down to form an air film. An exhaust cavity can be provided on the inner wall of the axis cavity, and an exhaust hole communicating with the exhaust cavity is provided on the R-axis mechanism, and the exhaust is discharged through the exhaust hole. Gas is blown out from the air floating outlet holes, so that an air film is formed between the Z-axis and the inner wall of the axis cavity, thereby reducing the friction when the Z-axis moves up and down. A negative pressure outlet hole corresponding to the adsorption inlet hole is provided on the Z-axis, and a positive pressure air duct and a negative pressure air duct are provided inside the R-axis mechanism. One end of the adsorption air duct communicates with the negative pressure outlet hole, and the other end is used to connect to a nozzle. One end of the positive pressure air duct is provided with a connector for connecting to an external positive pressure gas source, and the other end communicates with the air floating outlet hole. One end of the negative pressure air duct is provided with a connector for connecting to an external negative pressure gas source, and the other end communicates with the adsorption inlet hole. The external negative pressure gas source is connected to the suction nozzle through the negative pressure air duct and the adsorption air duct, and the suction nozzle adsorbs and grabs materials.

[0029] As an implementation manner, 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 are provided on one side of the pneumatic floating block corresponding to the pneumatic floating shaft plane (preferably, there are 2 throttle holes on one pneumatic floating block). The throttle holes communicate with a 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. During 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 entire 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), preventing the Z-axis from deflecting.

[0030] Preferably, there are 2 groups of pneumatic floating blocks, which are 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.

[0031] 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 two small throttle holes on the left and right pneumatic floating blocks and the pneumatic floating shaft plane on the Z-axis, which can prevent the Z-axis from rotating and also enable the Z-axis to float upward when subjected to an axial force.

[0032] As an implementation manner, the outer diameter of the upper end of the Z-axis is larger than that of the lower end, and the pneumatic floating shaft plane is recessed in 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.

[0033] As an implementation manner, there are multiple pneumatic floating air outlets, and the multiple pneumatic floating air outlets are evenly distributed along 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 along the inner wall of the shaft cavity.

[0034] 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 due to the different thicknesses of the products or the different positions of the products, when the large Z-axis moves down the same height, the suction nozzles of thin products or products at low positions cannot contact, resulting in an abnormal vacuum alarm for sucking the products.

[0035] 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 following the large Z-axis. The present invention is fixed at the end of the picking structure and moves following the rotary R-axis. Since the present invention adopts the air 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. 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 dimensional changes, thus preventing product damage caused by extrusion.

[0036] The present invention adopts a round rod with round hole structure. Therefore, in addition to being able to freely float up and down, the air floating shaft can also rotate freely at any position of 360° when subjected to a radial force. Since the Z-axis of the present invention is to rotate following 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, an anti-rotation structure needs to be provided for the Z-axis of the present invention, and this mechanism 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 type anti-rotation of the Z-axis is required. The present invention adopts a principle similar to that of an air 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 respectively facing the planes of the small Z-axis, and the air sources of the air floating blocks are connected to the external positive pressure air source through the positive pressure air ducts 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 within a gap of 0.005 - 0.01 mm. Then, through the high-pressure gas blown out by the throttling of the small holes of the two air floating blocks, there is a mutual balancing force between the two planes of the Z-axis and the two air floating blocks, ensuring that the Z-axis does not rotate. At the same time, there is a preset length (the preset length is consistent with the up and down movement stroke of the Z-axis) above and below the air floating shaft plane of the Z-axis to meet the up and down floating in the axial direction.

[0037] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalent scope.

Claims

1. A floating Z-axis device, 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 the air nozzle; one end of the positive pressure air passage is used to connect 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 an external negative pressure air source, and the other end communicates with the adsorption air inlets; Aerostatic pads are correspondingly arranged below the R-axis mechanism. Aerostatic pads planes are correspondingly arranged on the Z-axis. A number of throttle holes are provided on one side of the aerostatic pads corresponding to the aerostatic pads planes, and the throttle holes communicate with the positive pressure air passage.

2. The floating Z-axis device according to claim 1, wherein There are 2 groups of aerostatic pads, which are symmetrically arranged relative to the Z-axis. 2 groups of aerostatic pads planes are correspondingly arranged on the Z-axis.

3. The floating Z-axis device according to claim 1, wherein, The outer diameter of the upper end of the Z-axis is larger than that of the lower end. The aerostatic pads plane is recessed in the lower end. The up and down movement of the Z-axis is limited by the aerostatic pads.

4. The floating Z-axis device according to claim 1, characterized in that, 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.

5. The floating Z-axis device according to claim 4, 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.

6. The floating Z-axis device according to claim 1, wherein A displacement sensor for detecting the displacement of the Z-axis is provided on the R-axis mechanism.

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