An FMS automatic table exchange system for vertical machining centers

Abstract

The present invention discloses an FMS automatic exchange table system for a vertical machining center, including a pallet and a lifting plate, a lifting mechanism, a push-pull mechanism and a bottom plate arranged below the pallet, the lifting plate is fixed to the output end of the lifting mechanism, the lifting plate is connected to the pallet, the lifting mechanism and the push-pull mechanism are respectively installed on the bottom plate, the lifting mechanism is used to drive the lifting plate to move up and down, the pallet is connected to the output end of the push-pull mechanism, a guide mechanism is arranged between the lifting plate and the pallet, and the push-pull mechanism is used to drive the pallet to move left and right along the guide mechanism. The exchange table system of the present invention has strong applicability, can realize multi-workpiece, long-term automated processing, and can retain the original side double exchange table optional function of the vertical machining center. When the number of rough workpieces to be processed is small, it can be switched to the double exchange table mode. The exchange table system of the present invention can realize the project of a vertical machining center and a horizontal machining center in the same automated production line, and the processable parts are more diversified.

Description

Technical Field

[0001] The invention relates to a numerical control machine tool accessory, in particular to an FMS automatic exchange table system for a vertical machining center. Background Art

[0002] The commonly used automatic exchange table system for vertical machining centers often adopts the form of double pallet exchange, that is, a exchange device that can accommodate two pallets (Pallet A and Pallet B) is placed on the side of the machine tool. Pallet A is located in the internal processing area of ​​the machine tool, and pallet B is located in the exchange device. After the workpiece on pallet A is processed, pallet A and the finished workpiece are first moved out of the internal processing area of ​​the machine tool, and then the blank on pallet B is moved into the internal processing area of ​​the machine tool, thereby realizing the exchange of the two pallets. The disadvantage of this exchange table system is that it can usually only realize the exchange of two pallets, and the utilization rate of non-processing time is not high. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an FMS automatic exchange table system for a vertical machining center which has strong applicability and can realize automatic machining of multiple workpieces for a long time, in view of the shortcomings of the prior art.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: an FMS automatic exchange table system for a vertical machining center, including a pallet and a lifting plate, a lifting mechanism, a push-pull mechanism and a bottom plate arranged under the pallet, the lifting plate is fixed to the output end of the lifting mechanism, the lifting plate is connected to the pallet, the lifting mechanism and the push-pull mechanism are respectively installed on the bottom plate, the lifting mechanism is used to drive the lifting plate to move up and down, the pallet is connected to the output end of the push-pull mechanism, a guide mechanism is arranged between the lifting plate and the pallet, and the push-pull mechanism is used to drive the pallet to move left and right along the guide mechanism.

[0005] As a preferred embodiment, the lifting mechanism comprises two oil cylinders, each of which comprises a cylinder body, a piston shaft and a cylinder cover, the piston shaft is vertically fixed on the bottom plate, the cylinder body is sleeved on the piston shaft, the cylinder cover sealing sleeve is arranged on the upper end of the piston shaft, the lifting plate and the cylinder cover are respectively fixed on the upper end of the cylinder body, the cylinder body and the piston shaft form a clamping oil chamber, the cylinder body, the piston shaft and the cylinder cover form a loosening oil chamber, the clamping oil chamber is located below the loosening oil chamber, the bottom plate is provided with a first oil circuit and a second oil circuit, the first oil circuit is communicated with the clamping oil chamber, the second oil circuit is communicated with the loosening oil chamber, the first oil circuit and the second oil circuit are respectively communicated with the external oil supply system; a throttle valve is respectively installed on the first oil circuit and the second oil circuit of the two oil cylinders. The double piston oil cylinder structure is used as the lifting mechanism, and the throttle valve is used to control the flow of the first oil circuit and the second oil circuit to ensure that the two cylinder bodies float and descend smoothly and the floating and descending speeds are consistent to avoid eccentric loading.

[0006] Furthermore, the lifting plate is provided with two positioning through holes, each of the cylinder heads is embedded in one of the positioning through holes, a cover plate is fixed on the upper side of each of the cylinder heads, and the upper surface of the cover plate is flush with the upper surface of the lifting plate. The design of the positioning through holes further positions the cylinder head and the oil cylinder as a whole, and can improve the assembly accuracy of the oil cylinder.

[0007] Preferably, the push-pull mechanism comprises a piston rod, an exchange hook and an exchange block, a cylinder hole with an open end is provided on one side of the bottom plate, the cylinder hole is arranged along the length direction of the bottom plate, one end of the piston rod is inserted into the cylinder hole horizontally, a piston is integrally arranged at one end of the piston rod, the piston and the cylinder hole form a piston cavity, a third oil path communicating with the piston cavity is provided on the bottom plate, the other end of the piston rod extends from the open end of the cylinder hole, a cylinder cover is installed at the open end of the cylinder hole, the cylinder cover sealing sleeve is arranged on the piston rod, the exchange hook is fixed to the other end of the piston rod, the exchange block is fixed to the side of the tray close to the piston rod, a positioning groove is provided at the bottom of the exchange block, the exchange hook is located directly below the positioning groove, the width of the exchange hook is adapted to the width of the positioning groove, and the exchange hook is inserted into the positioning groove. Directly opening the cylinder hole on one side of the bottom plate to install the piston rod is conducive to improving the installation accuracy of the piston rod and making the overall structure of the FMS automatic exchange table system more compact. The bottom plate can be made of one-piece casting with high precision. The stroke design of the piston rod can effectively make up for the lack of fork arm stroke of the stacking locomotive, so that the fork arm can be fully extended to the bottom of the pallet.

[0008] Preferably, the guide mechanism includes a plurality of upper and lower rollers, which are divided into two rows and symmetrically arranged on both sides of the length direction of the lifting plate, and the axis of each upper and lower roller is parallel to the width direction of the lifting plate. The lower side of the tray is provided with two parallel guide grooves arranged opposite to each other, each guide groove is arranged along the length direction of the tray, and the height of each guide groove is greater than the outer diameter of each upper and lower roller. The distance between the two guide grooves is matched with the distance between the two rows of upper and lower rollers, and the two rows of upper and lower rollers extend into the two guide grooves respectively. When the tray moves left and right, the two rows of upper and lower rollers slide along the two guide grooves respectively, and using the multiple upper and lower rollers as guides can make the movement of the tray smoother.

[0009] Further, the guide mechanism further comprises a plurality of left and right rollers and a plurality of bosses, the plurality of bosses are divided into two rows and symmetrically arranged on both sides of the length direction of the lifting plate, an upper and lower roller is arranged near the left and / or right side of each boss, the top of the wheel surface of each upper and lower roller is slightly higher than the upper surface of each boss, the bottom of the wheel surface of each upper and lower roller is slightly lower than the lower surface of each boss, a left and right roller is embedded and uprightly installed on the outer side of the width direction of each boss, the outer wheel surface of each left and right roller slightly extends outward from the width direction of each boss, the height of each guide groove is greater than the height of each boss, the distance between the two guide grooves is matched with the distance between the two rows of bosses, the two rows of bosses extend into the two guide grooves respectively, and the left and right rollers in the two rows are respectively opposite to the groove bottoms of the two guide grooves. The plurality of left and right rollers and the plurality of bosses can further improve the reliability of the movement of the pallet, and realize the reliable pressing and supporting of the pallet by the lifting plate.

[0010] Preferably, a tray positioning hole is provided at the bottom of one side of the tray, a tray positioning pin matching the tray positioning hole is fixed on the bottom plate, and when the tray is in a clamped state, the tray positioning pin is inserted into the tray positioning hole. The cooperation between the tray positioning pin and the tray positioning hole can improve the positioning accuracy of the tray.

[0011] Furthermore, an airtightness detection device is provided between the tray and the bottom plate, and the airtightness detection device is close to the tray positioning pin. When the tray is in a clamped state, if the gap between the tray and the bottom plate is greater than a design value (e.g., 0.03 mm), the airtightness detection device alarms, prompting that possible foreign matter between the tray and the bottom plate needs to be removed, ensuring that the tray and the bottom plate are in close contact, ensuring that the overall flatness of the upper surface of the tray is within an acceptable range, and thus ensuring the overall accuracy of the tray.

[0012] Preferably, a fork arm positioning hole is provided at the bottom of one side of the pallet, and the fork arm positioning hole is matched with the fork arm positioning pin fixed on the fork arm of the stacker. When the pallet and the lifting plate are offset up and down by a certain distance, the fork arm of the stacker extends under the two sides of the pallet, and the fork arm positioning pin is inserted into the fork arm positioning hole, and the pallet is lifted upward by the fork arm of the stacker.

[0013] Preferably, up and down position sensing switches and left and right position sensing switches are respectively installed on both sides of the base plate, the up and down position sensing switches are used to detect whether the lifting plate is in place, and the left and right position sensing switches are used to detect whether the tray is in place.

[0014] Compared with the prior art, the present invention has the following advantages: the FMS automatic exchange table system of the present invention has strong applicability and can be generally used for the traditional double exchange APC (pallet automatic exchange device) in the vertical machining center to realize multi-workpiece and long-term automated processing, breaking the limitations of the traditional vertical machining center equipped with double exchange tables or the small number of blanks to be processed and the low utilization rate of non-processing time. At the same time, the original side double exchange table optional function of the vertical machining center can be retained. When the number of blank workpieces to be processed is small, it can be switched to the double exchange table mode. The FMS automatic exchange table system of the present invention can realize the engineering of the vertical machining center and the horizontal machining center in the same group of an automated production line, and the parts that can be processed are more diversified. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the assembly of the lifting plate and the cylinder body in the embodiment;

[0016] Figure 2 This is a schematic diagram of the assembly of the bottom plate and the piston shaft in the embodiment;

[0017] Figure 3 A longitudinal section schematic diagram of the exchange table system through the center line of the piston shaft in the embodiment (the pallet is in a clamped state);

[0018] Figure 4 for Figure 3 The enlarged image at point I in the middle;

[0019] Figure 5 for Figure 3 Middle AA section view;

[0020] Figure 6 for Figure 5 Enlarged view of II in the middle;

[0021] Figure 7 It is a longitudinal section schematic diagram of the exchange table system through the center line of the piston shaft in the embodiment (the state when the lifting plate floats 20mm);

[0022] Figure 8 for Figure 7 Middle BB section view;

[0023] Fig. 9 for Figure 8 Enlarged view of point III in the middle;

[0024] Fig.10 It is a longitudinal section schematic diagram of the exchange table system through the center line of the piston shaft in the embodiment (the state when the tray is pushed out 100 mm to the right);

[0025] Fig.11 for Fig.10 Middle CC section view;

[0026] Fig.12 It is a longitudinal cross-sectional schematic diagram of the exchange table system passing through the left and right position sensing switches in the embodiment (the state when the tray is pushed out to the right by 100 mm);

[0027] Fig.13 It is a longitudinal cross-sectional schematic diagram of the exchange table system passing through the left and right position sensing switches in the embodiment (the fork arm is lifted up 133mm to hold up the tray);

[0028] Fig.14 It is a longitudinal section schematic diagram of the exchange table system through the center line of the piston shaft in the embodiment when the fork arm is pulling the pallet out from the processing area of ​​the machine tool to the lifting platform. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings.

[0030] The FMS automatic exchange table system for a vertical machining center of the embodiment, as shown in the figure, includes a pallet 1 and a lifting plate 2, a lifting mechanism, a push-pull mechanism and a base plate 3 arranged below the pallet 1, the lifting plate 2 is fixed to the output end of the lifting mechanism, the lifting plate 2 is connected to the pallet 1, the lifting mechanism and the push-pull mechanism are respectively installed on the base plate 3, the lifting mechanism is used to drive the lifting plate 2 to move up and down, the pallet 1 is connected to the output end of the push-pull mechanism, a guide mechanism is arranged between the lifting plate 2 and the pallet 1, and the push-pull mechanism is used to drive the pallet 1 to move left and right along the guide mechanism.

[0031] In this embodiment, the lifting mechanism includes two oil cylinders, each oil cylinder includes a cylinder body 4, a piston shaft 41 and a cylinder cover 42, the piston shaft 41 is vertically fixed on the bottom plate 3, the cylinder body 4 is sleeved on the piston shaft 41, the cylinder cover 42 sealing sleeve is arranged on the upper end of the piston shaft 41, the lifting plate 2 and the cylinder cover 42 are respectively fixed to the upper end of the cylinder body 4, the lifting plate 2 is provided with two positioning through holes 21, each cylinder cover 42 is embedded in a positioning through hole 21, and a cover plate 43 is fixed on the upper side of each cylinder cover 42, and the upper surface of the cover plate 43 is in contact with the lifting plate 2. The upper surface is flush, the cylinder body 4 and the piston shaft 41 form a clamping oil chamber 44, the cylinder body 4, the piston shaft 41 and the cylinder head 42 form a loosening oil chamber 45, the clamping oil chamber 44 is located below the loosening oil chamber 45, and the first oil circuit 46 and the second oil circuit 47 are installed on the bottom plate 3, the first oil circuit 46 is communicated with the clamping oil chamber 44, the second oil circuit 47 is communicated with the loosening oil chamber 45, the first oil circuit 46 and the second oil circuit 47 are respectively communicated with the external oil supply system; a throttle valve 48 is respectively installed on the first oil circuit 46 and the second oil circuit 47 of the two oil cylinders.

[0032] In this embodiment, the push-pull mechanism includes a piston rod 51, an exchange hook 52 and an exchange block 53. A cylinder hole 31 with an open end is provided on one side of the bottom plate 3. The cylinder hole 31 is arranged along the length direction of the bottom plate 3. One end of the piston rod 51 is transversely inserted into the cylinder hole 31. A piston 54 is integrally provided at one end of the piston rod 51. The piston 54 and the cylinder hole 31 form a piston cavity 55. A third oil path 32 communicating with the piston cavity 55 is provided on the bottom plate 3. The other end of the piston rod 51 is inserted from the cylinder hole 31. The open end of the cylinder body hole 31 extends out, and a cylinder cover 33 is installed at the open end of the cylinder body hole 31. The sealing sleeve of the cylinder cover 33 is arranged on the piston rod 51. The exchange hook 52 is fixed to the other end of the piston rod 51. The exchange block 53 is fixed to the side of the tray 1 close to the piston rod 51. A positioning groove 56 is provided at the bottom of the exchange block 53. The exchange hook 52 is located directly below the positioning groove 56. The width of the exchange hook 52 is adapted to the width of the positioning groove 56, and the exchange hook 52 is inserted into the positioning groove 56.

[0033] In this embodiment, the guiding mechanism includes a plurality of upper and lower rollers 61, a plurality of left and right rollers 62 and a plurality of bosses 63. The plurality of upper and lower rollers 61 are divided into two rows and symmetrically arranged on both sides of the length direction of the lifting plate 2. The axis of each upper and lower roller 61 is parallel to the width direction of the lifting plate 2. Two parallel guide grooves 11 facing each other are opened on the lower side of the tray 1. Each guide groove 11 is arranged along the length direction of the tray 1. The height of each guide groove 11 is greater than the outer diameter of each upper and lower roller 61. The distance between the two guide grooves 11 is adapted to the distance between the two rows of upper and lower rollers 61. The plurality of bosses 63 are divided into two rows and symmetrically arranged on both sides of the length direction of the lifting plate 2. The left and right sides of each boss 63 are close to each other. An upper and lower roller 61 is provided, the top of the wheel surface of each upper and lower roller 61 is slightly higher than the upper surface of each boss 63, the bottom of the wheel surface of each upper and lower roller 61 is slightly lower than the lower surface of each boss 63, and a left and right roller 62 is embedded and uprightly installed on the outer side of the width direction of each boss 63, and the outer wheel surface of each left and right roller 62 slightly extends outward from the width direction of each boss 63. The height of each guide groove 11 is greater than the height of each boss 63, and the distance between the two guide grooves 11 is adapted to the distance between the two rows of bosses 63; the two rows of upper and lower rollers 61 and the two rows of bosses 63 extend into the two guide grooves 11 respectively, and the two rows of left and right rollers 62 are respectively opposite to the bottom of the two guide grooves 11.

[0034] In this embodiment, a pallet positioning hole 12 is provided at the bottom of one side of the pallet 1, and a pallet positioning pin 34 adapted to the pallet positioning hole 12 is fixed on the bottom plate 3. When the pallet 1 is in a clamped state, the pallet positioning pin 34 is inserted into the pallet positioning hole 12; an airtightness detection device 14 is provided between the pallet 1 and the bottom plate 3, and the airtightness detection device 14 is close to the pallet positioning pin 34; a fork arm positioning hole 13 is provided at the bottom of one side of the pallet 1, and the fork arm positioning hole 13 is aligned with the fork arm 7 of the stacking locomotive (not shown in the figure). 1 is adapted to the fork arm positioning pin 72 fixed on the bottom plate 1, when the pallet 1 and the lifting plate 2 are staggered up and down by a certain distance, the fork arm 71 of the stacker extends into the lower part of both sides of the pallet 1, and the fork arm positioning pin 72 is inserted into the fork arm positioning hole 13, and the pallet 1 is lifted up by the fork arm 71 of the stacker; the upper and lower position sensing switches 35 and the left and right position sensing switches 36 are respectively installed on both sides of the bottom plate 3, the upper and lower position sensing switches 35 are used to detect whether the lifting plate 2 is in place, and the left and right position sensing switches 36 are used to detect whether the pallet 1 is in place.

[0035] The working principle of the FMS automatic table exchange system for the vertical machining center described above will be explained below in combination with the different states of the pallet 1.

[0036] (1) If Figure 3 As shown, the tray 1 is in a clamped state.

[0037] When the pallet 1 is in the machining area of ​​the vertical machining center, it must be in a clamped state to prevent the pallet 1 from moving during cutting. To clamp the pallet 1, oil is supplied to the clamping oil chamber 44 through the first oil passage 46, generating a downward thrust to push the cylinder body 4 and the lifting plate 2 down, so that the two rows of bosses 63 press the pallet 1. At this time, the pallet positioning pin 34 is inserted into the pallet positioning hole 12, and the exchange hook 52 is inserted into the positioning groove 56. Under the combined action of friction and the pallet positioning pin 34 and the exchange hook 52, the pallet 1 is ensured to be in a clamped state, and the workpiece clamped on the pallet 1 can be processed.

[0038] (2) If Figure 7 As shown, the lifting plate 2 is in a state of floating a certain distance (set to 20 mm in this embodiment).

[0039] When the workpiece on the pallet 1 is processed, the system receives the exchange command. Oil is fed into the release oil chamber 45 through the second oil circuit 47, generating an upward thrust, pushing the cylinder body 4 and the lifting plate 2 to float, so that the two rows of bosses 63 are separated from the pallet 1, and the tops of the wheel surfaces of the two rows of upper and lower rollers 61 contact the top surfaces of the two guide grooves 11 respectively and push the pallet 1 to float, and the upper and lower position sensing switches 35 detect whether the lifting plate 2 floats to the right position. When the lifting plate 2 floats 20mm, the pallet positioning pin 34 is disengaged from the pallet positioning hole 12 by 4mm, and the exchange hook 52 is still in the state of being inserted into the positioning groove 56.

[0040] (3) If Figure 10 to Figure 12 As shown, the tray 1 is pushed to the right by a certain distance (set to 100 mm in this embodiment).

[0041] When the up-down position sensing switch 35 detects the lifting plate 2 floating up to the position signal, the piston rod 51 pushes the tray 1 to the right by 100 mm through the exchange hook 52 and the exchange block 53. When the left-right position sensing switch 36 detects the tray 1 pushing to the position signal, the tray 1 and the lifting plate 2 are staggered by 10 mm. Fig.12 The fork arm 71 of the stacker extends from the left side into the machine tool processing area until the bottom of the tray 1 on both sides, the fork arm positioning pin 72 is aligned with the fork arm positioning hole 13, as shown Fig.11 shown.

[0042] (4) If Fig.13 As shown, the fork arm 71 is lifted up by a certain distance (set to 133 mm in this embodiment) to hold up the tray 1; Fig.14 As shown, the fork arm 71 is holding the pallet 1 and pulling it out from the machining area of ​​the machine tool to the lifting platform.

[0043] The fork arm 71 moves upward until the fork arm positioning pin 72 is inserted into the fork arm positioning hole 13, and the fork arm 71 of the stacker lifts the pallet 1 upward, takes the pallet 1 out of the machine tool processing area and puts it into the shelf.

[0044] The fork arm 71 is installed on the lifting platform of the stacker, and the stacker is installed on the shelf. The shelf has multiple layers of storage spaces in the vertical direction, and each layer of storage spaces can be spliced ​​into any number of storage spaces. The fork arm 71 can be extended and retracted left and right on the lifting platform, the lifting platform can be moved up and down on the stacker, and the stacker can move forward and backward on the shelf, so as to place the pallet 1 in any storage space of the shelf, and finally transport the pallet 1 to the loading and unloading station to remove the finished workpieces on the pallet 1. In this embodiment, specifically, the fork arm 71 lifts the pallet 1 upward by 133 mm under the action of the lifting platform and the stacker, and the fork arm positioning pin 72 on the fork arm 71 is inserted into the fork arm positioning hole 13, so that the pallet 1 is completely disengaged from the lifting plate 2 by 20 mm (no horizontal position overlap), so that the exchange block 53 is disengaged from the exchange hook 52.

[0045] (5) See Fig.13 and Fig.14 The fork arm 71 is withdrawn from the shelf to the lifting platform, and the lifting platform moves up and down on the stacker. The stacker can move forward and backward on the shelf to the designated location to take the blank workpiece to be processed. Then, the blank workpiece is sent to the machine tool processing area in the order of (4), (3), (2), and (1).

[0046] The above is a set of action cycles in which the finished workpieces in the machine tool processing area are replaced and the rough workpieces are replaced in the machine tool processing area. Clamping a sufficient number of rough workpieces on the shelf at one time can achieve a longer period of automated processing.

[0047] The FMS automatic exchange table system of the present invention has strong applicability and can be used in the traditional double exchange APC (pallet 1 automatic exchange device) in the vertical machining center to realize multi-workpiece and long-term automated processing, breaking the limitations of the traditional vertical machining center equipped with double exchange tables or the small number of blanks to be processed and the low utilization rate of non-processing time. At the same time, it can retain the original side double exchange table optional function of the vertical machining center. When the number of blank workpieces to be processed is small, it can be switched to the double exchange table mode. The FMS automatic exchange table system of the present invention can realize the engineering of the vertical machining center and the horizontal machining center in the same group of an automated production line, and the parts that can be processed are more diversified.

Claims

1. An FMS automatic table exchange system for a vertical machining center, characterized in that: The lifting mechanism is a kind of at least one oil passage of the present invention, and its upper and lower ends are provided with the oil passage of the present invention, and the oil passage of the present invention is a kind of oil passage of the present invention, and its upper and lower ends are provided with the oil passage of the present invention. The open end of the cylinder hole is provided with a cylinder cover, the cylinder cover sealing sleeve is provided on the piston rod, the exchange hook is fixed on the other end of the piston rod, the exchange block is fixed on the side of the pallet close to the piston rod, a positioning groove is provided at the bottom of the exchange block, the exchange hook is located directly below the positioning groove, the width of the exchange hook is adapted to the width of the positioning groove, the exchange hook is inserted into the positioning groove, and an up-and-down position sensing switch and a left-and-right position sensing switch are respectively provided on both sides of the bottom plate, the up-and-down position sensing switch is used to detect whether the lifting plate is in place, and the left-and-right position sensing switch is used to detect whether the pallet is in place, a fork arm positioning hole is provided at the bottom of one side of the pallet, the fork arm positioning hole is adapted to the fork arm positioning pin fixed on the fork arm of the stacker, and when the pallet and the lifting plate are staggered up and down by a certain distance, the fork arm of the stacker extends into the bottom of both sides of the pallet, the fork arm positioning pin is inserted into the fork arm positioning hole, and the pallet is lifted up by the fork arm of the stacker.

2. The FMS automatic table exchange system for a vertical machining center according to claim 1, characterized in that: The lifting mechanism includes two oil cylinders, each of which includes a cylinder body, a piston shaft and a cylinder cover. The piston shaft is vertically fixed on the base plate, the cylinder body is sleeved on the piston shaft, and the cylinder cover sealing sleeve is arranged on the upper end of the piston shaft. The lifting plate and the cylinder cover are respectively fixed to the upper end of the cylinder body. The cylinder body and the piston shaft form a clamping oil chamber, and the cylinder body, the piston shaft and the cylinder cover form a loosening oil chamber. The clamping oil chamber is located below the loosening oil chamber. A first oil circuit and a second oil circuit are installed on the base plate. The first oil circuit is communicated with the clamping oil chamber, and the second oil circuit is communicated with the loosening oil chamber. The first oil circuit and the second oil circuit are respectively communicated with the external oil supply system. A throttle valve is installed on the first oil circuit and the second oil circuit of the two oil cylinders.

3. The FMS automatic table exchange system for a vertical machining center according to claim 2, characterized in that: The lifting plate is provided with two positioning through holes, each of the cylinder heads is embedded in the corresponding positioning through holes, a cover plate is fixed on the upper side of each of the cylinder heads, and the upper surface of the cover plate is flush with the upper surface of the lifting plate.

4. The FMS automatic table exchange system for a vertical machining center according to claim 1, characterized in that: The guiding mechanism includes a plurality of upper and lower rollers, which are divided into two rows and symmetrically arranged on both sides of the length direction of the lifting plate. The axis of each upper and lower roller is parallel to the width direction of the lifting plate. Two parallel guide grooves facing each other are opened on the lower side of the tray. Each guide groove is arranged along the length direction of the tray. The height of each guide groove is greater than the outer diameter of each upper and lower roller. The distance between the two guide grooves is matched with the distance between the two rows of upper and lower rollers. The two rows of upper and lower rollers extend into the two guide grooves respectively.

5. The FMS automatic table exchange system for a vertical machining center according to claim 4, characterized in that: The guide mechanism also includes a plurality of left and right rollers and a plurality of bosses, the plurality of bosses are divided into two rows and symmetrically arranged on both sides of the length direction of the lifting plate, an upper and lower roller is provided near the left and / or right side of each boss, the top end of the wheel surface of each upper and lower roller is slightly higher than the upper surface of each boss, the bottom end of the wheel surface of each upper and lower roller is slightly lower than the lower surface of each boss, a left and right roller is embedded and uprightly installed on the outer side in the width direction of each boss, the outer wheel surface of each left and right roller slightly protrudes outward from the outer side in the width direction of each boss, the height of each guide groove is greater than the height of each boss, the distance between the two guide grooves is matched with the distance between the two rows of bosses, the two rows of bosses extend into the two guide grooves respectively, and the two rows of left and right rollers are respectively facing the bottom of the two guide grooves.

6. The FMS automatic table exchange system for a vertical machining center according to claim 1, characterized in that: A tray positioning hole is provided at the bottom of one side of the tray, and a tray positioning pin matched with the tray positioning hole is fixed on the bottom plate. When the tray is in a clamped state, the tray positioning pin is inserted into the tray positioning hole.

7. The FMS automatic table exchange system for a vertical machining center according to claim 6, characterized in that: An air tightness detection device is arranged between the tray and the bottom plate, and the air tightness detection device is close to the tray positioning pin.

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