JPS6365466B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pallet changing device in a horizontal machining center, which is capable of attaching and detaching a pallet that supports a workpiece to and from a machining support shaft.

[Conventional technology]

In a general machining center, the workpiece (hereinafter referred to as the work) is held on a horizontal pallet, and a plurality of such pallets are arranged horizontally, and the desired pallet is transported horizontally to the workpiece processing position. It is now being sent to With this type of structure, chips and cutting oil produced during machining may fall onto the pallet or onto the pallet conveyance path, causing problems, and a large space is required to store the pallets, which increases the floor space required for the entire machine. There are drawbacks. Therefore, the present applicant has developed a machining center that eliminates these drawbacks and has filed a patent application (see Japanese Patent Application Laid-Open No. 189748/1983). The machining center disclosed in JP-A-57-189748 holds a pallet holding a workpiece at the tip of a horizontal support shaft with the mounting surface of the pallet perpendicular, and performs processing such as cutting in this state. This solves the problem of chips, making it a so-called horizontal machining center. Further, in the preferred embodiment disclosed in this publication, a large number of pallets are held by a vertically arranged endless conveyor, thereby reducing the floor space required for accommodating the pallets.

[Problem to be solved by the invention]

The horizontal machining center disclosed in the above-mentioned publication has the excellent effect of solving the problem of contamination of the pallet or its conveyance path by chips and cutting oil, and reducing the required floor space of the entire machine. Problems that should be improved were found. That is,
In the above-mentioned horizontal machining center, a pallet exchange device is provided between the pallet magazine and the support shaft, and includes a rotating arm that holds the pallets of the pallet magazine and the magazine of the support shaft at both ends.
This occupies a considerable amount of space, and the structure is complicated and expensive.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pallet exchange device for a horizontal machining center that is simple in structure, requires a small installation space, and can be manufactured at low cost.

[Means to solve the problem]

The present invention, which has been made to achieve the above object, as shown in the embodiment of the drawings, supports the pallet 4 so that the mounting surface of the workpiece is perpendicular and can be removed by sliding the pallet laterally. In a horizontal machining center, the support shaft 3 includes a support shaft 3 having a pallet holding portion at its tip, and a main shaft 6 for supporting a tool, which is disposed near the tip of the support shaft 3 at right angles to the support shaft and horizontally. A pallet magazine 8 is arranged on the side opposite to the main shaft side,
A pallet changer 9 is provided on the side of the support shaft on the main shaft side.

This pallet magazine 8 includes a rotor 24 which is rotatable about a horizontal axis perpendicular to the support shaft 3 located at the pallet exchange position, and four rotors held around the rotor 24 so as to be perpendicular to each other. The pallet holding member 25 is removable by sliding the pallet laterally, and each pallet holding member 2 is removable by sliding the pallet laterally.
means for indexing and rotating the rotor so as to move the rotor to a pallet exchange position located next to the pallet holder at the tip of the support shaft located at the pallet exchange position.

The pallet changer 9 reciprocates a change shaft 9A that engages with a pallet hook 44 on the pallet side surface on a straight line passing approximately through the center of each of the pallet holding section and the pallet holding member located at the pallet exchange position. The two-stage cylinder 9B moves the changer shaft 9A.
a standby position away from the pallet held by the pallet holding portion of the support shaft 3, an intermediate position engaged with the pallet on the support shaft 3, and a pallet magazine 8.
It is equipped with two pistons 9C and 9D arranged in series and a fluid supply circuit that drives each piston independently so that it can be moved to the forward position where it engages the upper pallet and then stopped.

Furthermore, when the pallet magazine is indexed and rotated with the change shaft 9A stopped at the forward position and the pallet held by the pallet holding member is moved in the vertical direction, the change shaft 9A and the pallet hook 44 on the side of the pallet are moved. It is configured to engage and disengage.

[Effect]

According to the pallet exchange device having the above configuration, after performing a predetermined process on the work on the pallet 4 held on the support shaft 3, the support shaft 3 is moved to the pallet exchange position, while the pallet exchange position of the magazine 8 is moved to the pallet exchange position. Position the pallet holding member 25 that does not hold a pallet, and in this state, position the change shaft 9A of the pallet changer 9 at an intermediate position,
The pallet 4 is released by releasing the fixation of the pallet 4 from the support shaft 3, engaging the change shaft 9A of the pallet changer 9 with the pallet hook 44 of the pallet 4, and then moving the change shaft 9A to a predetermined forward position.
can be pushed out from the support shaft 3 and transferred to the pallet holding member 25 of the magazine 8. Next, with the change shaft 9A of the pallet changer 9 stopped at the forward position, the pallet magazine 8 is indexed and rotated.
The pallet holding member 25 that has received the pallet sent by the pallet is moved vertically to release the engagement between the changer hook 9A of the pallet changer 9 and the pallet hook 44, and the pallet holding the new pallet is moved. The holding member can be moved to the pallet changing position and the pallet hook 44 of that pallet can be engaged with the change hook 9A of the pallet changer 9. after that,
By retracting the change shaft 9A of the pallet changer to an intermediate position, the pallet 4 can be transferred from the magazine 8 onto the support shaft 3.
Here, the change shaft 9A moves on a straight line passing approximately through the center of each of the pallet holding part and the pallet holding member located at the pallet exchange position, so it moves the pallet 4 by pushing or pulling the center of the side surface of the pallet 4. This allows for smooth movement of pallets. Further, since the change shaft of the pallet change gear is driven by a two-stage cylinder, it can be accurately stopped at an intermediate position or a forward position. After passing the pallet 4 to the support shaft 3, the pallet chain shaft 9 of the pallet changer 9 is
A returns to the standby position laterally away from the support shaft 3. This completes the pallet exchange operation.

〔Example〕

Hereinafter, preferred embodiments of the present invention shown in the drawings will be described in detail.

FIG. 1 is a perspective view showing the schematic arrangement of components of a horizontal machining center equipped with a pallet exchange device according to the present invention. In the figure, 1 indicates a horizontally spreading machine floor, and behind machine floor 1 there is a vertical bed 2.
is placed. On one side of vertical bed 2,
A block (not shown) that holds the support shaft 3 is disposed so as to be movable in the vertical direction (X direction), and the support shaft 3 is movable in the first horizontal axis direction (Y direction) and is mounted on the block. It is held indexable and rotatable about a horizontal axis. A pallet holder is provided at the front end of the support shaft 3, and the pallet 4 is mounted with its work mounting surface perpendicular. Thus,
The pallet 4 and the workpieces (not shown) held therein are movable in the X and Y directions and rotatable.

Slide base 2 is installed on the other side of vertical bed 2.
A is fixed, and a spindle support block 5 is held on the slide base 2A so as to be movable in a second horizontal axis direction (Z direction) perpendicular to the first horizontal axis direction (Y direction). A main shaft 6 extending in the second horizontal axis direction is rotatably held in the main shaft 6 . A tool (not shown) is attached to the tip of the main shaft 6.
In this way, the pallet 4 supported on the tip of the support shaft 3
The upper workpiece can be machined as desired using the tool on the spindle 6.

As shown in FIGS. 5 and 6, the pallet 4 has a cylindrical portion 40, an engagement groove 42 parallel to the mounting surface 41, a central recess 43, etc. on the back surface of the mounting surface 41 of the workpiece, and It has a pallet hook 44 on the side. On the other hand, the support shaft 3 has a clamp plate 3A (see FIG. 11A) that engages with the engagement groove 42 of the pallet 4 on the pallet holding portion at its tip. mating,
Then, the pallet 4 is attached to the support shaft 3 by moving the clamp plate 3A backward with respect to the support shaft 3 and pressing the cylindrical portion 40 of the pallet against the coupling member 3B (see FIG. 9A) at the tip of the support shaft. Can be firmly fixed. Therefore, the support shaft 3 is indexed and rotated to a position where the clamp plate is horizontal, the clamp plate is slightly advanced relative to the support shaft to remove the clamp, and then the pallet 4 is slid laterally to remove the pallet. It can be removed from the support shaft 3.

The pallet changing device of the present invention has a pallet magazine 8 disposed on the opposite side of the support shaft 3 from the main shaft side, and a pallet changer 9 disposed on the main shaft side. When the support shaft 3 is lowered to the pallet exchange position, the pallet 4 on the support shaft 3
It acts to transfer a new pallet from the magazine 8 to the pallet magazine 8 and transfer a new pallet from the magazine 8 to the support shaft 3, and the details will be described later.

Next, the pallet magazine 8 will be described in detail with reference to FIGS. 2 to 4. The magazine 8 has a horizontal fixed shaft 23 fixed to left and right frames 21 and 22, and a rotor 24 rotatably supported by the fixed shaft 23. Note that the rotor 24 may be fixed to the fixed shaft 23, and the fixed shaft 23 may be rotatable. The rotor 24 has a dice shape, and pallet holding members 25 are arranged on four outer surfaces of the rotor 24. These pallet holding members 25 are held by the rotor 24 so as to be rotatable about four axes that are perpendicular to the central axis of the rotor 24 and at 90 degrees to each other. The end of each pallet holding member 25 is provided with a pair of engagement protrusions 25A extending in parallel in a plane perpendicular to its central axis, and the engagement protrusions 25A engage with the engagement grooves 42 of the pallet 4. This is for supporting the pallet 4. However,
The pallet holding member 25 can hold the pallet 4 so that its mounting surface is perpendicular to the central axis of the pallet holding member 25, and can be attached and detached by sliding the pallet along the engagement protrusion 25A. I can do it. Further, as can be clearly seen in FIG. 4, the rotor 24 can hold four pallets 4 at right angles to each other.

A large-diameter gear 26 is fixed to one end of the rotor 24, while a hydraulic motor 27 and a gear train 28 for transmitting rotation of the hydraulic motor 27 to the gear 26 are provided on the frame 22. These constitute means for indexing and rotating the rotor 24. That is, the hydraulic motor 27 cooperates with a control device (not shown) to index and rotate the rotor 24 every 90 degrees from the position shown in FIG. 4 (the position where the pallet 4 is vertical and horizontal). Thus, when the rotor 24 is at rest, the pallet will always be in a horizontal and vertical position. In order to index the rotor quickly and stop it at an accurate position, a rotor encoder is placed in the gear train 28 to detect when the rotor approaches the stop position, and in response to this signal, the hydraulic motor It is preferable to slow down. Also, rotor 2
4 is indexed and stopped, in order to fix the rotor in that position, a recess is provided in the rotor 24 or the gear 26 fixed to the rotor, and the frame 22
Preferably, the recess is provided with a pneumatically or hydraulically actuated shot pin for engaging the recess.

In FIG. 2, the portion of the pallet holding member 25 facing the outer surface of the rotor 24 has a plurality of (four in this embodiment) recesses 30 at equal intervals in the circumferential direction.
On the other hand, a pallet holding member 25 is formed on the rotor 24 at a predetermined rotational position relative to the rotor 24 (the pallet 4 supported on the pallet holding member 25 is
position for pulling out with pallet changer 9)
A shot pin 31 is provided which can engage one of the recesses 30 when located in the recess. The shot pin 31 is normally pressed into the recess 30 by a spring 32 to prevent rotation of the pallet retaining member 25, the recess and the shot pin forming means for securing the pallet retainer in a predetermined rotational position relative to the rotor. A lever 35 (only one lever is shown in FIG. 2) is provided near each shot pin 31 and is swingable around a fulcrum 34, and one end of the lever 35 engages with the outer surface of the shot pin 31. The other end of the lever 35 is a free end, and by pushing this other end to the right in FIG. 2, the shot pin 31 can be moved downward. A pneumatic cylinder 36 is provided to push the free end of the lever 35 and swing the lever. This pneumatic cylinder 36 is fixed to the frame 22, and is arranged so that only the upper lever of the four levers 35 of the rotor 24 can be operated.

Each pallet holding member 25 has a pin 3 at its center.
7 is held movably. This pin 37 engages with a recess 43 on the back surface of the pallet 4 held in a predetermined position on the pallet holding member 25 to prevent the pallet from moving, and is normally pressed against the pallet 4 by a spring 38. It is possible to retreat when attaching or removing a pallet from the pallet holding member. The rear end of the pin extends to the vicinity of the fixed shaft 23, and as shown in FIG. 7, the upper surface and one side surface of the fixed shaft 23 are cut out to allow the pin to move backward. Thus, the pin 37 cannot be moved back in the portion of the fixed shaft 23 without a notch, and therefore, the pallet will not be inadvertently detached from the pallet holding member at this portion, thereby preventing trouble. The pin 37 further has a cam surface 37A.
Another pin 39 is in constant contact with. pin 39
is provided so as to project out of the pallet holding member 25 and actuate the limit switch 50 when the pin 37 is in the normal position engaged with the recess 43 of the pallet. The limit switch 50 is provided stationary near the pallet holding member 25 on the upper surface and side surface of the rotor 24 (however, on the tip end side of the support shaft 3), and when the pallet holding member 25 is located at a predetermined rotational position, the pin 39 is arranged to be operated. Therefore, the limit switch 50 determines whether the pallet 4 is attached to a predetermined position of the pallet holding member 25 on the top and side surfaces of the rotor 24, and also determines whether the pallet holding member 25 is at a predetermined rotational angle position with respect to the rotor 24. A means for determining whether or not is configured is configured. In addition, Fig. 2,
In FIG. 3, reference numeral 51 denotes a guide fixed to the outer surface of the rotor 24, and when the pallet 4 is attached to or removed from the pallet holding member 25, it engages with the engagement groove 42 of the pallet and guides it.

The magazine 8 having the above structure is as shown in FIG.
The pallet holding member that holds the pallet 4A in a vertical position on the front side is lowered to the pallet exchange position so that the rotation center axis of the rotor 24 is horizontal and perpendicular to the support shaft 3 of the machining center when viewed from the top. The support shaft 3 is arranged at a position lined up with the pallet holding portion at the tip of the support shaft 3, that is, at a pallet exchange position. Thus, each pallet holding member 25 held by the rotor 24 of the magazine 8 can be sequentially moved from above and below to the pallet exchange position by indexing rotation of the rotor 24. Note that a guide 1 is provided between the magazine 8 and the support shaft 3 to guide the pallet when moving the pallet 4 on the support shaft to the pallet holding member of the magazine 8 or vice versa.
5 is provided. If the magazine 8 can be placed sufficiently close to the support shaft 3, the guide 15 may be omitted.

As shown in FIG. 8, the pallet changer 9 is composed of a two-stage cylinder 9B having a changer hook 9A at its tip. Chenjiafutsu 9A is the 5th
It is a disc or rectangular plate having a shape that can be engaged with the groove of the pallet hook 44 on the side surface of the pallet 4 shown in FIGS. The two-stage cylinder 9B has two separate pistons 9C and 9D arranged in series, and is connected to a fluid supply circuit so as to drive each piston 9C and 9D independently, as shown in FIG. 9B, 10B,
As shown in FIG. 11B, the change shaft 9A, which is disposed on a straight line passing approximately through the center of the pallet holding part of the support shaft 3 located at the pallet exchange position and the pallet holding member 25 of the magazine 8, is On a straight line, a standby position (9th B) away from the pallet 4 held by the support shaft 3
), an intermediate position (10th position) engaging the pallet 4
(Fig. B) and an advanced position (Fig. 11B) in which it engages a pallet on the magazine 8, and is stopped at each position.

In FIG. 1, 10 is a tool magazine, 11 is a tool changer, 12 is an operation panel, and 13 is an NC device.

Next, the pallet exchange operation in the above apparatus will be explained. In FIG. 1, the pallet 4A on the front side of the magazine 8 is removed, and workpieces are attached to the other pallets. The change shaft 9A of the pallet changer 9 is in the standby position. Support shaft 3
When the machining of the workpiece on the pallet supported by the support shaft 3 is completed, the support shaft 3 is indexed and rotated to a position where the engagement groove 42 of the pallet 4 held thereon is horizontal.
It descends from the position shown and moves to the pallet exchange position. This state is shown in FIGS. 9A and 9B, and as can be clearly seen from FIG. 9A, the pallet 4 supported by the support shaft 3 is at a position slightly retracted from the pallet removal position. Next, the pallet changer 9 is operated to advance the changer hook to the intermediate position shown by the two-dot chain line in FIG. 9A. In this state, when the clamp plate 3A of the support shaft 3 is advanced and the pallet is unclamped, the pallet 4 is
As shown in Figure 0A, the pallet hook 44 moves forward slightly and engages with the change shaft 9A. At this time, the pallet 4 has left the support shaft 3 by sliding laterally and is in a position where it can be engaged with the pallet holding member 25 of the magazine via the guide 15.
When the change shaft 9A is further advanced from the position shown in FIGS. 10A and 10B, the pallet 4 is pushed by the change shaft 9A and moved to the positions shown in FIGS. 11A and 11.
As shown in Figure B, it moves onto the magazine 8 and is held by the pallet holding member 25. Next, magazine 8
When the rotor of is rotated, pallet 4 becomes the 11th B
The magazine 8 moves upward or downward as shown by the arrow in the figure, and a new pallet of the magazine 8 comes to the illustrated position 11A and engages with the changer hook 9A.

When the change shaft 9A is then retracted to the intermediate position, the new pallet of the magazine 8 is pulled and engaged with the clamp plate of the support shaft 3, as shown in FIGS. 10A and 10B. Next, when the clamp plate is moved back and the pallet is clamped, the pallet is moved back to the position shown in FIG. 9A, and the change shaft 9A is disengaged, so that the change shaft 9A is returned to the standby position. This completes the pallet exchange operation.

The pallet (which holds processed workpieces) returned to the magazine 8 is held horizontally on the upper surface of the rotor by indexing rotation of the rotor 24, and the workpieces are removed in this state. Next, a new workpiece to be processed is mounted on this horizontal pallet 4. At this time, the pallet 4 can be placed in a convenient position for the work by rotating the pallet holding member 25 to a desired rotation angle position with respect to the rotor, and the work for attaching and removing the pallet 4 can be easily performed. When the attachment of the workpiece is completed, the pallet holding member 25 is returned to a predetermined rotation angle position for removing the pallet by the pallet changer 9, in preparation for the next pallet exchange. In addition, when it is necessary to replace the pallet held in the magazine 8 with a new pallet, the rotor 2
4. Just pull out the horizontal pallet on the top surface by hand and install a new pallet. If the pallet holding member has not returned to the predetermined rotational angle position for pallet exchange after completing these operations, the limit switch 50 will be inactive and the pallet will not be able to move onto the pallet holding member 25. If the pallet is not inserted to the specified position, the pin 37 at the center of the pallet holding member 25 will not fully fit into the recess 43 on the back of the pallet, and the limit switch 50 will not be activated, so the next operation such as indexing and rotation of the rotor will proceed. This prevents malfunctions. Furthermore, as shown in FIGS. 11A and 11B, even when the pallet 4 moves to the pallet holding member 25 at the pallet exchange position, the pallet may not reach the predetermined position on the pallet holding member 25 due to some trouble. Otherwise, the limit switch 50 will not be activated and future malfunctions will be prevented.

〔Effect of the invention〕

As described above, the pallet exchange device of the present invention arranges the pallet magazine close to the side of the support shaft,
A pallet changer is disposed on the opposite side, and the pallet is moved from the support shaft to the magazine and vice versa by engaging the changer hook of the pallet changer with the hook of the pallet and reciprocating it. As a result, there is no need to install a complex pallet changing device between the support shaft and the magazine as in the past, and the pallet changer can be placed deep inside the main shaft, requiring extra installation space. The entire machine can be made smaller. Further, since the pallet changer moves the pallet by pushing or pulling approximately the center of the side surface of the pallet, the pallet can be moved smoothly.
In addition, since a two-stage cylinder is used as the pallet changer, the changer shaft can be accurately stopped at the standby position, intermediate position, and forward position.
Moreover, it has a simple structure, does not take up much space, and can be manufactured at low cost. Furthermore, the engagement and disengagement between the pallet hook and the change shaft in the pallet magazine are as follows:
Since this can be done simultaneously by indexing and rotating the pallet magazine, there is no need for movements such as rotating or moving the changer shaft up and down, and from this point of view as well, the mechanism of the pallet changer can be simplified. Furthermore, since a 4-pallet magazine is used as the pallet magazine, it is compact and space-saving, and has the advantage of being able to easily attach and detach workpieces to and from pallets on the top of the magazine. are doing.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of a horizontal machining center equipped with a pallet exchange device of the present invention, FIG. 2 is a vertical sectional view of the magazine 8, FIG. 3 is a plan view of the main parts of the magazine 8, and FIG. In Figure 2 -
5 is a perspective view of the pallet 4, FIG. 6 is an enlarged side view of the pallet hook 44 of the pallet 4, and FIG. 7 is a schematic view of the fixed shaft 2 of FIG. 2.
3 and a sectional view showing the relationship between pins 37 around it,
FIG. 8 is a cross-sectional view schematically showing the pallet changer 9, FIGS. 9A, 9B to 11A, 11
FIG. B is a diagram for explaining the pallet exchange operation, and FIGS. 9A, 10A, and 11A show the state seen from above, and FIGS. 9B, 10B, and 11B show the state seen from the front. 3...Support shaft, 4,4A...Pallet, 6...Main shaft,
8... Pallet magazine, 9... Pallet changer, 9A... Change shaft, 9B... Two stage cylinder, 44... Pallet hook, 25... Pallet holding member.

Claims (1)

[Claims] 1. A support shaft that supports a pallet so that the mounting surface of the workpiece is perpendicular and has a pallet holder at its tip that can be removed by sliding the pallet laterally, and the support shaft In a horizontal machining center, a main shaft for supporting a tool is arranged near the tip of the tool at a right angle to the support shaft and horizontally, and a pallet magazine is arranged on the side opposite to the main shaft side of the support shaft. , a pallet changer disposed on the side of the main shaft side of the support shaft, the pallet magazine having a rotor rotatable about a horizontal axis perpendicular to the support shaft located at the pallet exchange position. and four pallet holding members held at right angles to each other around the rotor, which are removable by sliding the pallet laterally, and each pallet holding member. , means for indexing and rotating the rotor so as to move the rotor to a pallet exchange position located next to a pallet holder at the tip of the support shaft located at the pallet exchange position, and the pallet changer is configured to a change shaft that engages with the pallet hook; and a two-stage cylinder that reciprocates the change shaft on a straight line passing through substantially the center of each of the pallet holding section and the pallet holding member located at the pallet exchange position, A stage cylinder moves the change shaft into a standby position away from the pallet held by the pallet holding portion of the support shaft, an intermediate position where it engages a pallet on the support shaft, and an advanced position where it engages a pallet on the pallet magazine. so that it can be moved and stopped,
It is equipped with two pistons arranged in series and a fluid supply circuit that drives each piston independently, and furthermore, with the changer hook stopped at the forward position, the pallet magazine can be rotated by indexing the pallet magazine. A pallet changing device for a machining center, characterized in that it is configured to engage and disengage a change shaft.