JPS60181805A - Pressure controller - Google Patents

Abstract

PURPOSE:To obtain a pressure controller which keeps the weight balance between a cylinder and a product by controlling the secondary pressure produced to a held cylinder in response to a weight change due to the replacement of a tool or an attachment. CONSTITUTION:When an arch-shaped machining center is kept in a driving state, a cylinder 30 hangs a head stock and an attachment and holds them. The cylinder 30 is provided with the prescribed breakdown strength capacity from a reducing valve 34 via a pipeline 32. The oil which supplies said breakdown strength power is supplied to the cylinder 30 via a tank 42, pump 40, a check valve 38, a pipeline 36, etc. Under such conditions, a tool hanged by the cylinder 30 is replaced. If the weight is increased, switch valves 60, 74, 88 and 98 constituting a pressure control mechanism 48 or 54 are properly energized to switch the oil which supplies the pressure corresponding to the increase of weight to the valve 34.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure regulating device, and more particularly, when holding a predetermined article through a cylinder, the present invention adjusts the fluid pressure change in the cylinder due to the change in weight caused by replacing the article. The present invention relates to a pressure regulating device configured to ensure a weight balance between an article and a cylinder by adjusting by a combination of a plurality of other valve devices.

Machine tools, such as recessed machining centers, have conventionally adopted a configuration in which a hydraulic cylinder is disposed at the top of a column, and a headstock is suspended and held by a rod extending from the hydraulic cylinder. In this case, the weight of the headstock itself and the weight of the tools attached to the headstock are added to the hydraulic cylinder to achieve a weight balance. A machining center with such a configuration is shown in FIG. In this machining center 2, a column 8 is connected to a base 6 which is slidably mounted on a guide member 4 having a circular cross section.
A head stock 14 including a motor 12 is disposed in a chamber 10 defined approximately in the center of the column 8 so as to be vertically movable. Headstock 14 is column 8
It is suspended and held by a cylinder 16 exposed at the top.

That is, the tip of the cylinder rod 18 extending outwardly downward from the end of the cylinder 16 is connected to the -\radstock 14 at its center. headstock 1
4 further mates with the ball screw 20 and engages with a pair of guide members 22, 24 at both ends thereof. One end of the ball screw 20 is connected to a rotating shaft (not shown) of a motor 24 disposed at the top of the column 8, and as the motor 28 rotates, the ball screw 20 also rotates to accurately position the headstock 14. is achieved.

Therefore, in such a configuration, as described above, the weight of the headstock 14 and the weight of the tools and attachments attached to the headstock 14 are directly added to the hydraulic cylinder 16, and there is a gap between the oil pressure in the cylinder and the weight. Balance is ensured and the position of the headstock 14 is fixed.

However, as is well known, machining centers are based on the premise that the tools attached to the headstock are replaced depending on the workpiece.

Furthermore, depending on the tool, it may be necessary to attach various attachments. Therefore, if the weight of the tool or attachment is within a predetermined range, the weight may be balanced even with a single hydraulic cylinder as described above. However, when it is necessary to replace various tools and attachments over an extremely wide range of weights, there is a problem in that a single hydraulic cylinder cannot handle the replacement. Of course, it is possible to select a hydraulic cylinder with a relatively large allowable range that can handle the weight of various tools and attachments, but there are certain physical constraints due to the overall configuration of the machining center. be.

On the other hand, it is also possible to connect a proportional solenoid pressure control valve to the hydraulic cylinder and balance the weight between the hydraulic cylinder and the headstock side under the control of this control valve, but the proportional solenoid pressure control valve However, since it is expensive, it has the disadvantage of significantly increasing manufacturing costs.

Therefore, as a result of intensive research and trial production, the inventors of the present invention connected a plurality of pressure reducing valves each producing a different pressure reducing effect to the pipeline of the hydraulic cylinder that balances the weight with the headstock side. When the weight on the heel stock side changes due to the replacement of attachments, etc. and secondary pressure is generated, this is adjusted by the combination of the plurality of pressure reducing valves and the weight is finally balanced between the hydraulic cylinder and the head stock side. It has been found that with this configuration, the various problems mentioned above can be eliminated.

The purpose of the present invention is to adjust the secondary pressure generated in the cylinder that holds the door in response to various changes in weight when replacing an article, such as a tool or an attachment, and to reduce the pressure between the cylinder and the article. The object of the present invention is to provide a pressure regulating device for balancing the weight of a machine.

In order to achieve the above object, the present invention includes a main pressure reducing valve interposed in a pipe extending from a tank and connecting to a cylinder boat, and a plurality of pressure regulating mechanisms are connected to the main pressure reducing valve, The pressure adjustment mechanism includes switching valves and relief valves each having a different set pressure, and adjusts the secondary output to the cylinder of the main pressure reducing valve by selectively energizing or deenergizing the switching valves. DESCRIPTION OF THE PREFERRED EMBODIMENTS The pressure regulating device according to the present invention, which is characterized by such a configuration, will be described in detail below with reference to preferred embodiments in relation to a machining center and with reference to the accompanying drawings.

In FIG. 2, reference numeral 30 indicates a hydraulic cylinder mounted on the upper part of a column of a machining center (not shown).

A balanced piston type pressure reducing valve 34 with a relief is connected to one boat of the hydraulic cylinder 30 via a pipe 32, and the pressure reducing valve 34 is connected to a hydraulic pump 40 via a check valve 38 disposed in a pipe 36. , connected to the cock 42. A pressure gauge 44 and a cock 46 are connected to the pipe line 32.

In the present invention, the pressure reducing valve 34 has a secondary pressure of 53
．． The pressure is reduced to 4 kgf lcr&, and this pressure reducing valve 34 is further connected to a plurality of sets of pressure regulating mechanisms comprising a switching valve and a relief valve. In this case, as one embodiment, four sets of pressure adjustment mechanisms 48, first to fourth,
．． 50.52 and 54 are combined, the first pressure adjustment mechanism 4B is for pressure adjustment of 47kg47eta, and the second pressure adjustment mechanism 50 is for pressure adjustment of 50.7kgf.
The third pressure adjustment mechanism 52 is used to adjust the pressure of 45 kgf /cTil, and the fourth pressure network adjustment mechanism 54 is used to adjust the pressure of 20.3 kgf /cJ.
These are selected for adjusting the pressure of cot. That is, in the first pressure adjustment mechanism 48, the pipe line 58 branching from the pilot pressure supply main pipe line 56 connected to the vent boat of the pressure reducing valve 34 is connected to the first switching valve 6, which is a four-way two-position valve.
0 and one boat of the first switching valve 60 is connected to the primary side of a first relief valve 64 whose secondary side pressure is 47 kgf/cf.

The secondary side of the relief valve 64 is connected to a main recovery pipe 68 which is connected to the tank 42 via a pipe 66.

Note that the main pipe line 56 is blocked by the first pressure adjustment mechanism 48.

Next, the other pipe line 70 connected to the switching valve 60 is blocked by the second pressure regulating mechanism 50, but the pipe line 72 branching from this pipe line 70 is connected to one of the second switching valves 74. Connect to input port. A conduit 76 is led out from one output port of the second switching valve 74, and this conduit 76 is blocked on one side, but on the other side is a second relief valve that sets the downstream pressure to 50.7 kgf/ctl. It is connected to the main conduit 68 by a conduit 80 that interposes the main conduit 78 . The conduit 82, which is connected at one end to the second switching valve 74, is connected to the second switching valve 74, and the other output port of the switching valve 74 is connected to the second switching valve 74.
It is connected to the main pipe 6 via pipe 84.

Next, the pipe line 62 of the first pressure adjustment mechanism 48 is blocked, but the pipe line 86 branching from this pipe line 62 is blocked.
It is connected to one of the human-powered boats of the third switching valve 8B that constitutes the pressure adjustment mechanism 52. A secondary pressure of 45k is applied to the pipe line 90 connected to the other input port side of the third switching valve 88.
A third relief valve 92 with gf /c+a is connected, and the secondary side of the third relief valve 92 is connected to a conduit 94 extending from the output port of the third switching valve 88 to finally is connected to conduit 08. Note that the third switching valve 88
The other output port of is blocked by conduit 95.

Furthermore, the line 90 is connected to a line 96 of the fourth pressure regulating mechanism 54 which is blocked on one side but branches on the other side. Pipe line 96 is connected to one input port of fourth switching valve 98, and pipe line 100 is connected to the other input port. Although the pipe line 100 is blocked on the -blade side, a pipe line 102 is branched from this pipe line 100, and a fourth relief valve 104 with a secondary side pressure of 20.3 kgf/et4 is interposed therein. . The pipe line 102 is connected to a pipe line 106 extending from one output port of the fourth switching valve 9B, and finally connected to the main pipe e8. The conduit 10B extending from the other output port of the fourth switching valve 98 is blocked.

In the figure, reference numeral 110 is an accumulator connected to the main pipe 56, reference numerals 112 and 114 are throttle valves interposed between the main pipe 56 and the accumulator 110, and The code 116.118 is
These are check valves arranged in parallel with the throttle valves 112 and 114, respectively.

The pressure regulating device according to the present invention is basically constructed as described above, and its operation and effects will be explained next.

First, in a portal machining center, when it is in operation, the cylinder 30 suspends the headstock, tools, and possibly the axotiment. In this embodiment, the cylinder 30 is configured to be able to withstand a maximum pressure of 53.4 kgf/- from the pressure reducing valve 34 via the conduit 32. The oil that provides such pressure resistance is supplied from the tank 42 to the hydraulic pump 40, the check valve 38, the pipe line 36, the pressure reducing valve 34, and the pipe line 3.
6 and is fed to the cylinder 30.

Therefore, in such a situation, when tools and the like suspended by the cylinder 30 are replaced and their weight increases, according to the device of the present invention, a combination of the first to fourth pressure adjustment mechanisms is used. The increase in weight will be accommodated by biasing.

For example, if the total weight of the headstock, tools, etc.
When the pressure is converted to 0 and is 20.3 kgf/cra, in the device of the present invention, the switching valve 8 of the third pressure adjustment mechanism 52
8 and the switching valve 98 of the fourth pressure adjustment mechanism 54 may be turned on. The oil flow path in this case is shown in FIG. 3a.

That is, in this figure, the oil led out from the pressure reducing valve 34 through a conduit 56 passes through a conduit 58 and reaches the first switching valve 60 as shown by the solid arrow. Since this switching valve 60 is in the OFF state, oil passes through the pipe line 62 to the pipe line 86 and reaches the third switching valve 88. Since the third switching valve 88 is on, oil flows through the pipe line 90. This oil enters the relief valve 92 on the one hand, reduces the pressure to 45 kgf/crA due to its pressure reducing effect, and
6. Since the fourth switching valve 98 connected to the pipe line 96 is in the ON state as described above, oil reaches the pressure reducing valve relief valve 104 via the pipe line 100 and the pipe line 102, which are blocked on the one hand. The relief valve 104 reduces the pressure to 20.3 kgf 1cra, and the oil passes through the main line 68 to the pressure reducing valve 34. As is well known, in order to keep up with the low pressure, even if the relief valve 92 is
Even if the oil pressure is reduced to gf/cd, the pressure of the pressure reducing valve 34 is maintained within 20.3 kg4/- according to the pressure reducing effect of the fourth relief valve 104. Therefore,
The cylinder 30 can be maintained at an appropriate height within a range of 20.3 kgf/ctK when the total weight of the head stock, tools, etc. is converted into pressure. That is, when the total weight is within the range of 20.3 kgf/a+1 in terms of pressure, the third switching valve 88 and the fourth switching valve 98 are energized to replace the tool, etc.

Next, when the tool is replaced and its weight increases, the pressure is converted to 4
The case where the weight falls within the range of 5 kgf/- will be explained with reference to FIG. In this case, in the device of the present invention, only the switching valve 88 of the third pressure regulating mechanism 52 is energized.

Therefore, as in the previous embodiment, since the switching valve 88 is turned on, the oil that has reached the pipe 86 passes through the pipe 90 as shown by the solid arrow and reaches the relief valve 92, where the oil reaches the relief valve 92.
The pressure is reduced to kgf/ctM from the main pipe 68 to the pressure reducing valve 34.
leading to. Note that when the switching valve 88 is turned on, the pipe line 90.96
Since the switching valve 98 is in the OFF state, the oil that reaches the fourth switching valve 9B reaches the pipe 108, but this pipe 10
8 is blocked as shown in the figure, so no pressure reduction effect is achieved here.

As a result, the pressure reducing valve 34 supplies oil to the cylinder 30 within a range of 45 kgf/cnt.

Similarly to the above, when the total weight of the headstock, tools, etc. is 45 kgf/c+II in terms of pressure, it is sufficient to energize only the third switching valve 88 in preparation for its replacement.

When the tool is replaced again and its weight increases, the pressure is converted to 47
The case where the amount is within the range of kg4/cJ will be explained with reference to FIG. 3C.

In this case, in the device of the present invention, none of the switching valves 60, 74, 88, and 98 constituting the pressure regulating mechanisms 48 to 54 is energized. Therefore, the oil that has reached the switching valve 60 via the lines 56 and 58 passes through the line 62 and reaches the relief valve 64. The relief valve 64 controls this oil pressure to 47 kgf/-
The pressure is reduced to reach the main pipe 68 from the pipe 66, and finally returned to the pressure reducing valve 34. At this time, the oil that passes through the pipe 62 and reaches the pipe 86 reaches the pipe 95 because the third switching valve 88 is in the OFF state.
The pressure reducing effect is achieved only by the relief valve 64. In this condition, 47kgf/
Tools, attachments, etc. may be replaced within the weight range corresponding to -.

Furthermore, replacing tools increases their weight.

The case where the pressure is within the range of 50.7 kgf/et4 will be explained with reference to FIG. 3d.

In this case, in the device of the present invention, the switching valve 60 of the first pressure regulating mechanism 48 is turned on. That is, when the switching valve 60 is turned on, the oil that reaches the switching valve 74 via the pipe line 70.72 flows through the relief valve 78 because the switching valve 74 is off.
reach. The pressure of the oil is reduced to 50.7 kgf/- by the relief valve 78 and reaches the main pipe 68 via the pipe 84. Since oil does not flow into the third pressure adjustment mechanism 52 and the fourth pressure adjustment mechanism 54, the pressure reduced by the relief valve 78 is 50.7 kgf/
cJ becomes the pressure of the pressure reducing valve 34.

Finally, a case will be described with reference to FIG. 3e, in which the weight of the tool is further increased by replacing the tool and the weight is within a range corresponding to 53.4 kgf/cIil in terms of pressure.

In this case, the switching valve 60 of the first pressure regulating mechanism 48 and the switching valve 74 of the second pressure regulating mechanism 50 are turned on. As a result, the oil flowing through the pipe 58 reaches the pipe 70 via the switching valve 60, passes through the pipe 72, and reaches the switching valve 74.

Since this switching valve 74 is also on, the oil is flowing through the pipe 8.
2, but since this pipe line 82 is blocked, there is no pressure reduction effect in this hydraulic control system. That is, the pressure reducing valve 34 continues to maintain the pressure range of 53.4 kgf/cra and delivers oil to the cylinder 30.

In the above hydraulic control system, the pipe line 56 is connected to the throttle valve 112.
114, connected to the accumulator 110 via check valves 116, 118. Therefore, even if there is a sudden increase in load when replacing the 22 rings, this accumulator 110
absorbs the oil and gradually supplies oil to the pressure regulating mechanism, thereby avoiding damage to the mechanism.

According to the present invention, even if there is a change in the weight of the head stock, tools, or attachments of a machining center suspended by a hydraulic cylinder as described above, the weight can be adjusted by combining the predetermined pressure reducing valves attached. It becomes possible to supply the appropriate pressure corresponding to the cylinder to the cylinder, and it is possible to maintain the headstock etc. in a stable state at all times. Therefore, when machining workpieces with tools, significant effects such as improved machining accuracy and reduction of defective products can be obtained.Furthermore, as is clear from the above description, the device of the present invention can be used with ordinary switching valves and relief valves. Because it mainly consists of a combination of Furthermore, another great effect of the present invention is that the suspension capacity of the cylinder can be increased by increasing the number of combinations of switching valves and relief valves.

The present invention has been described above with reference to preferred embodiments, but
It goes without saying that the present invention is not limited to this embodiment, and that various improvements and design changes can be made without departing from the gist of the present invention.

[Brief explanation of drawings]

FIG. 1 is a front schematic explanatory diagram of a machining center according to the prior art, FIG. 2 is a hydraulic control system circuit diagram of a pressure regulating device according to the present invention, and FIGS. 3 a to 3 e are hydraulic control system diagrams shown in FIG. FIG. 3 is an explanatory diagram showing the flow of hydraulic pressure when controlling the hydraulic pressure to the machining center is achieved by combining and operating a switching valve and a relief valve that constitute a system circuit. 30...Hydraulic cylinder 32...Pipe line 34...Reducing valve 36...Pipe line 38...Check valve 40...Hydraulic pump 42...Tank 44...Pressure gauge 46...Cock 48.50.52. 54...Pressure adjustment mechanism 56.58.
・Pipe line 60...First switching valve 62...Pipe line 64...First relief valve 66...Pipe line 68...Main pipe line 70.72...Pipe line 74...Second switching valve 76...Pipe Path 78...Second relief valve 80.82.84.86...
Pipe line 88...Third switching valve 90...Pipe line 92...Third
Relief valve 94.96...Pipeline 98...4th switching valve 1
00.102...Pipeline 104...Fourth relief valve 1
06.108...Pipe line 110...Accumulator 1
12.114 ... Throttle valve 116.118 ... Check valve patent applicant Toshiba Machine Co., Ltd. Procedural amendment (acid) November 17, 1980 1, Case description [Appendix 1159 Special Fraud Office No. 3703
8 No. 2, Name of the invention Pressure regulating device 3, Connection with the person making the amendment Case 1 Patent applicant Address 4-2-11 Neza, Chuo-ku, Tokyo Name Toshiba Machine Co., Ltd. 4, Agent 5, Date of amendment order z1 Voluntary action 7, Contents of amendment (11531 bribery ear size (2) Figure 2,
Figure 3 (Tsukasa to +el are corrected as attached to W paper, first of all, amendment book 1 of Japanese Patent Application No. 59-37038, ``...motor 28...'' on page 4, line 2 of the specification is changed to ``...'' First, amend it as [Mori 24...]. Patent applicant: Toshiba R Machine Co., Ltd. Applicant's agent: Patent attorney: Goriki Chiba ゛

Claims (5)

[Claims] (1) A main pressure reducing valve is interposed in a pipe extending from the tank and connected to the cylinder boat, a plurality of pressure regulating mechanisms are connected to the Ben 1 port of the main pressure reducing valve, and the pressure regulating mechanism Each of the switching valves includes a switching valve and a relief valve having a different set pressure, and is configured to adjust the secondary side output to the cylinder of the main pressure reducing valve by selectively energizing or deenergizing the switching valve. A pressure regulating device featuring: (2) The pressure regulating device according to claim 1, wherein the main pressure reducing valve is a balanced piston type pressure reducing valve with a relief. (3) The pressure regulating device according to claim 1 or 2, wherein the main pressure reducing valve has a secondary output having a higher pressure than the pressure reducing valve constituting the pressure regulating mechanism. (4) A pressure regulating device according to any one of claims 1 to 3, in which an accumulator is connected to a conduit connecting the main pressure reducing valve and the pressure regulating mechanism. (5) A pressure regulating device according to any one of claims 1 to 4, wherein the cylinder is incorporated in a concave machining center.