JPS62155852A - Hydraulic controls for treatment chairs - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hydraulic control device for a treatment chair, comprising a plurality of chair parts adjustable in relative movement and supplied with hydraulic medium from a pump. A conduit circuit and a conduit connection for the cylinder-piston unit arranged in parallel with the cylinder-piston unit mounted between the chair parts are provided, at which the conduit connection connects the supply conduit and the return conduit. A control valve is arranged to control the cylinder/piston unit, and in this case, the hydraulic medium is throttled and supplied to the cylinder/piston unit in order to avoid sudden movements of the cylinder/piston unit. Concerning the type of thing that is.

BACKGROUND OF THE INVENTION A known control device of this type, which is disclosed in DE 31 05 979 A1, provides a throttled supply of hydraulic medium to the supply and return conduits of a cylinder-piston unit, respectively. A control valve is provided that opens and closes slowly for the purpose. These control valves are control valves each equipped with an electric motor drive for slow opening and closing of the control valves.

This known control device is extremely expensive. This means that
This is due not only to the relatively complex and high control costs of slow-opening and closing drives, but also to the fact that these controls are designed for single-acting cylinder-piston units. It will be done. This means that if one wishes to use this known control device for modern treatment chairs in which several relatively movably adjustable chair parts are frequently controlled in both adjustment directions, a large number of relatively complex control valves is required. This not only increases production costs but also increases space requirements.

OBJECTS OF THE INVENTION It is therefore an object of the invention to provide a control device of the type mentioned at the outset, which does not require a large amount of space and which can be manufactured relatively inexpensively.

Means for Solving the Problem In order to solve this problem, in the configuration of the present invention, at least one part of the cylinder/piston unit is a double-acting cylinder/piston unit, and both of the double-acting cylinder/piston units pressure chambers are connected to the supply and return conduits via supply and return conduit sections, and a control valve is arranged in each return conduit section for the double-acting cylinder-piston unit; Each conduit section was provided with a reverse valve that was open in the direction of flow.

Effects of the Invention The following are particularly mentioned as major advantages obtained by the present invention. By using a double-acting cylinder-piston unit, the number of specially controlled control valves is thus reduced, which results in a desirably low manufacturing cost and space requirement. The arrangement of the invention also makes it possible to arrange the control valve only in the return conduit section. In contrast, in the prior art, it was necessary to provide a control valve also in the supply lead/α section.

The control device according to the invention can be used in particular for treatment chairs with a plurality of relatively movable chair parts, such as dental treatment chairs. The control device according to the invention is also suitable for other medical treatment chairs, such as examination and surgical equipment, and also for barbershop chairs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A dental treatment chair, generally indicated by the reference numeral 1 in FIG. is formed by a seat part 4, a backrest 5 and a head support part 6, these parts 3.4.6 being relatively movable and adjustable;
and can be fixed in the respective desired adjustment position.

A parallelogram link mechanism 7 is disposed in the hollow chamber of the chair lower part 2 to adjust the height of the chair lower part 2, and this parallelogram link mechanism 7 is supported by the bottom of the chair lower part 2,
It engages with the cover plate 8 of the chair lower part 2, in which case a single-acting cylinder-piston unit 9 is provided as a drive device. It is supported by a lever arm 11 on the lower side of the quadrilateral link mechanism 7,
The piston rod 12 engages a lower lever arm 13.

In the hollow space of the chair lower part 2, further parts of the control system for the treatment chair 1, which will be described later, are arranged, namely a motor-pump unit 14, a hydraulic tank 15 and a control block, which will be described later.

The chair upper part 3 can be adjusted horizontally along the longitudinal direction of the seat in the chair lower part 2. For this purpose, the cylinder/piston unit 17 arranged in the hollow chamber of the seat part 4 works,
This cylinder-piston unit 17 is pivotally mounted on bearing eyes 18, 19 of the chair lower part 2 and of the seat 4.

The inclination of the backrest 5 can be adjusted by a double-acting cylinder-piston unit 21, which is attached to the hollow chamber of the seat 4 and extends between the seat 4 and the backrest 5. is pivotally connected to bearing eyes 22, 23 of. The pivot axis of the backrest 5 is designated by 22a.

The head support 6 is held on the backrest 5 so that it can be selectively extended and retracted on the one hand, and pivotable about a pivot axis 24 on the other hand. A double-acting cylinder/piston unit 25 works for the movement of the head support section 6 into and out.
This cylinder-piston unit 25 is arranged in the hollow space of the backrest 5 and is pivoted on a bearing eye 23,27. The inclination of the head support 6 is adjustable by means of a double-acting cylinder-piston unit 28, which cylinder-piston unit 2B is pivotally mounted on the bearing eyes 29, 30 of the relatively movable parts.

The control device shown in FIG. 2 has a hydraulic circuit with a supply conduit, generally designated 31, and a return conduit, generally designated 32. Both conduits 31.32 have cylinder-piston units 9.17.21, 25.
Hydraulic medium is supplied from a hydraulic tank 15 by a motor/pump unit 14 for supplying hydraulic medium to 28 . The feed and return flows of the hydraulic medium are precontrolled by a control valve 1
6, this control valve 16 shuts off the supply conduit 31 and the return conduit 32 in its rest position, which is loaded by a spring 33, and in its pre-controlled operating position it closes the supply conduit 31 and the return conduit 32. Allow the flow.

In this case, in the rest position, the supply conduit section 35 located upstream of the pre-controlled control valve 16 and the pre-controlled control valve 16
It can be seen that a restricted flow occurs between the return conduit section 36 located downstream of the conduit section 36 and
The return line section 35 has a return line branch 37 connected to the single-acting cylinder-piston unit 9 and a return line branch 38 connected to the double-acting cylinder-piston unit 17°21.25.28. It is branched into.

From the feed line section 39 downstream of the precontrolled control valve 16, a feed line section 41 branches off, which feed line section 41 is connected to the pressure chamber 42 of the single-acting cylinder-piston unit 9. is familiar with Viewed in the flow direction, a two-port, two-position directional valve 43 and a reversal valve 44, which opens into the pressure chamber 42, are arranged one after the other in the supply line section 41. Behind the check valve 44, the supply conduit section 41 is connected to a return conduit branch 3T, which, viewed in the direction of the return flow, is provided with a reverse valve that opens in the direction of the return flow. 45, an adjustable restrictor 46, and a two-port, two-position directional valve 47 are arranged one after the other.

Double-acting cylinder/piston annular chamber) 17° 21.25
．． The two pressure chambers 28, the piston chamber 48 and the piston annular chamber 49, are connected to the supply conduit 31 and the return conduit 32.

For this purpose, supply conduit sections 51-54 and 55-58 and return conduit sections 59-66 are provided, in which case each two associated conduit sections are connected to one another, and the feed flow and conduit section 6 serving for return flow.
1 to 74 to the piston chamber 48 or piston annular chamber 49 of the multi-ribbon cylinder/piston unit 17.21.25.28. The supply conduit 31 is branched at a branch point 75 .

Supply conduit sections 51-54 extend from a supply conduit branch indicated at 76, whereas supply conduit sections 55-54 extend from a supply conduit branch indicated at 76.
58 originates from the supply conduit branch designated 77. A check valve 78 is disposed in each supply conduit section 51-58 and opens in the direction of supply flow indicated by arrow 79.

Each return conduit section 59-66 has a control valve 81-88 formed by a two-port, two-position directional valve in the return flow direction indicated by arrow 80 and an adjustable restrictor 89 open in the return flow direction 80. One check valve 91 is arranged.

Each supply conduit branch 76 between the branch point 75 and the supply conduit sections 51 to 58 or the return conduit sections 59 to 66
．． At 77, control valves 92 and 93 formed by two-port two-position directional switching valves that can be opened and closed are arranged.

The control valve 16 is pre-controlled by a pre-control valve 95, which is likewise formed by a two-port, two-position directional valve and is arranged in the control line 9δ. This control conduit 96 runs from the supply conduit section 35 located upstream of the control valve 16 to the return conduit section located after the reversal valve 97 and downstream of the control valve 16 in the feed flow direction. It extends behind 36.

A control line section 99 branches off in the supply flow direction upstream of the precontrol valve 95 at a branch point 98 , which leads to a control connection of the control valve 16 to be precontrolled. Two throttles pioo, ioi are arranged in the control line 96 in front of the branch point 98 in the feed direction, and a throttle 102 is arranged between the branch point 98 and the pre-control valve 95. Pressure limiting valve 104 serves to limit the pressure in the hydraulic circuit.

The control valves 81 to 84 are combined with their supply conduit sections 51 to 54 and return conduit sections 59 to 66 and supply conduit branch 76 and control valve 92 into a preassembled control block 105, which control block 105 is slender. Indicated by a solid line. The other supply line branch 77 is likewise combined with the associated control valves 85 to 88 and the supply line sections 55 to 58 and the return line sections 63 to 66 into a preassembled control block 106. Pre-controlled control valve 1
6 also forms a preassembleable control block 107 with the precontrol valve 95, the supply line section 39, the return line branch 37 and the associated control valves 43,47. control block 105
The connection points 107 to 107 are designated 108 in each conduit. The control blocks 105 , 106 are arranged in the hollow space of the seat 4 , whereas the control block 107 is arranged in the chair lower part 3 .

Figure 6 and 4! '2I clearly shows the structure of the precontrolled control valve 16. This control valve 16 is connected to the supply conduit 3
2 connections 112° 113 for 1 and return conduit 32
two connections 114, 115 for and control conduit section 9
9 and one connection 116 for a 4-point, 2-position control valve. The valve susol 117 has two switching positions (
3 and 4), and the spring 33
is preloaded toward the rest position (see Fig. 3) by. The control bin 111E is connected to the valve spool 117.
18 extends axially on the side of the valve suction 117 opposite the control pressure chamber 119 and extends in the casing closure part 1
21 and projects outwards, thus making it possible to visually display or monitor the respective position of the valve suction 117.

Most of the control line 96 is integrated into the control valve 16 due to its compact design. For this purpose, the valve suction 117 has a radial bore 122 in the area of the connection 112.
The radial hole 122 is connected to the control pressure chamber 119 via an axial hole 123. In the feed flow direction, throttles 100 and 101 are arranged one after the other in the axial bore 123 and are formed by screwable nozzles. The throttle 102 shown in FIG. 2 is located in the housing 111 in the area of the control connection 116 .

The passage between the connections 112 to 1150 is connected to the valve spool 1.
17 is formed by a notch on the entire circumference. each two notches 123,1 radially opposite each other;
27, 128° 129 are provided, these recesses are located at the control edge 1 between the supply connections 112 and 113.
30 and with a control edge 131 between return connections 114 and 115. Valve susol 1 shown in FIG.
In the rest position of 17, the supply connections 112, 113 and 11
4,115 is closed, whereas in the operating position shown in the fourth country it is open. Notch 1
The length of 29 is such that in the rest position (FIG. 3) there is a passage between supply connection 112 and return connection 115 at point 132. In order to throttle the flow rate, throttle cutouts 133 to 137 are provided in the area of the control edge 130, 131 as well as in the area of the channel 132, each of these throttle cutouts radially facing each other. The diaphragm recesses have lengths L1 of different sizes, which results in a progressive increase in the diaphragm effect.

The operation of the control device is as follows: In FIG.
．． 17.21.25.28 are shown in the rest position with the hydraulics locked. To introduce the regulating action, the input of the motor-pump unit 14 and the switching of one of the control valves 43, 47 for the single-acting cylinder-piston unit 9 and the two control valves 92, 93 for pre-movement are required. and one of the two control valves 81 to 88 associated with each cylinder number piston unit 17, 21, 25, 28 of the mobile type. These control valves, including the front control valve 95, can be electrically controlled.

The control sequence for the single-acting cylinder-piston unit 9 for height-adjusting the treatment chair 1 is as follows: The motor and piston unit 9, which is preferably activated at the same time by the operating button, is as follows:
After inputting the pump unit 15 and switching over the pre-control valve 95 and the control valve 44, first the return line branch 37.3
8 is supplied with pressure. This only takes 0.1 seconds.

The pre-control valve 95 shifted into the shut-off position brings the pre-controlled control valve 16 into the operating position indicated at number 41. Control valve 44 is shifted to the open position. The cylinder-piston unit 9 is now automatically moved in due to the weight of the chair upper part 2, with the hydraulic medium being returned from the pressure chamber via the return line branch 3T and the return line section 36.

The downward movement is stopped by switching the control valve 44;
This can be done at the same time as shutting off the motor and pump unit 14.

The control sequence for the cylinder-piston unit 21, which can be actively loaded in both feed directions to adjust the inclination of the backrest 5 in the direction of descent, is as follows: Input of the motor-pump unit 14; Switching of the control valve 90 into the blocking position, automatically following this switching of the control valve 16 into the open position, switching of the control valve 92 in the supply conduit branch 76 into the open position and the control valve in the return conduit section 64 By switching 86 into the open position, the piston impaction chamber 49 of the cylinder pot unit 21 is co-fed with hydraulic medium, while the piston chamber 48 is connected to the return conduit 32 . That is, the cylinder-piston unit 21 runs in for a long time at least until the control valve 86 is switched back to the shut-off position. In this case, the input or switching of the associated control valves can also take place simultaneously.

As can be seen from Figure 3, valve susol 117
When the pump is shifted out of its rest position, the supply line section 39 is supplied with a throttled hydraulic medium.

This hydraulic medium is supplied from D to the maximum volumetric flow in about 0.3 seconds. This supply process is progressive. That is,
The length 1 of the second diaphragm notch 134 is the diaphragm notch 13.
This is because the throttle notch 133 only works if it is already working, since it is small compared to the large length L of No. 3. The same applies to the connection of the return conduit branch 37, 38 with the return conduit section 36 (see throttle cutouts 135, 136 of different lengths). As a result of this restricted supply or discharge, the piston rod of the cylinder-piston unit begins to move gently. That is, abrupt movements that are uncomfortable for the patient on the treatment chair are desirably avoided.

When the front control valve 95 is shifted to the open position,
The throttle 102, which determines the adjustment movement of the valve suction 117 by its magnitude, also influences the throttled supply or discharge.

The above is clear from the diagrams shown in FIGS. 5 and 6.

In FIG. 5, pressure P is plotted on the vertical axis and time t is plotted on the horizontal axis.As can be seen from this diagram, the return conduit branch 37.
Due to the throttled pressure build-up at 38 and the throttled supply to the supply line 31, the maximum pressure level Pmax is 0.
It is reached only after 1 second + 0.3 seconds. As a result, a diagonal section 141 is obtained in the characteristic line which shows a gentle movement profile of the cylinder-piston unit. A correspondingly gentle movement course is also obtained at the end of the movement K of the cylinder-piston unit. That is the return conduit branch 37.
This is because the discharge of the hydraulic medium from 38 into the return conduit section 36 also takes place after a time period of approximately 3 seconds.

In FIG. 6, the velocity V of the piston rod of the cylinder-piston unit is plotted on the vertical axis, and the time t is plotted on the horizontal axis. Both are 1
Since the relationship is like a second order function, the diagram in FIG. 6 depicts the same characteristic line as the diagram in FIG.

As a result of the throttled supply (throttle 100, 101) of the pre-controlled control valve 16 after the input of the motor/pump unit 140, the throttling valve 34 (see FIG. 2) or throttling is first activated in the return line branch 37.38. Notch 137 (third
The fact that the working pressure is created by the position (see FIG. 4) has great significance. That is, by this,
Not only is a delay of 0.1 seconds introduced during the entry and exit of the cylinder-piston unit 17° 21.25.28 and during the exit of the cylinder-piston unit 90, but also the pressure in the return conduit branch 37.38 is The delay is activated, which, in addition to the restricted supply of hydraulic medium, serves for the desired gentle movement of the cylinder-piston unit.

[Brief explanation of drawings]

FIG. 1 is a side view of a dental treatment chair equipped with a cylinder-piston unit for adjusting the chair parts; FIG. 2 is a hydraulic circuit diagram for a control device for a treatment chair according to the invention; FIG. 3 is a sectional view showing the control valve in its rest position, FIG. 4 is a sectional view showing the control valve in its operating position, and FIGS. 5 and 6 show the throttled supply process of the cylinder-piston unit. This is Figure 8. 1... Treatment chair, 2... Lower chair, 3... Upper chair, 4... Seat, 5... Backrest, 6... Head support, 7... Parallelogram link Mechanism, 8... Cover plate, 9.17.21, 25.28... Cylinder.
Piston unit, 11.13--Lever arm, 1
2...V! 4--Motor/pump unit, 15-mount hydraulic tank, 16--Control valve, 1
8゜19.22.23.23.27...Support eye, 2
2a, 24... Rotating shaft, 31... Supply conduit, 32...
...Return conduit, 33...Spring, 34...Aperture, 35
゜39.41.51-58... Supply conduit section, 36゜59-66... Return conduit section, 31.38... Return conduit branch path, 42... Pressure chamber, 43.47...・2 port 2 position directional switching valve, 44.45... Reverse 1): Valve, 46... Throttle, 48.49... Pressure chamber, 67-7
4... Conduit section, 75.98... Branch point, 76° 77... Supply conduit branch path, 78... Check valve, 19° 80... Arrow, 81-88... Control Ben, 89...
Throttle, 91... Counter pressure valve, 92.93... Control valve, 9
5... Front control valve, 96... Control conduit, 97... Check valve, 99... Control conduit section, ioo~102...
Throttle valve, 104...Pressure limiting valve, 105-107...
Control block, 108--Connection point, 112-116
...Connection part, 117--Valve susol, 118 River con I/0-/I/ turn, 119... Control pressure chamber, 121
...Casing closing part, 122.123...Bypass, 123-129...Notch, 130.131.
...Control edge, 132...Passway, 133-137...
Aperture notch, 141... classification,

Claims (1)

[Claims] 1. A hydraulic control device for a treatment chair, comprising a plurality of chair parts whose relative movement can be adjusted, a conduit circuit supplied with hydraulic medium from a pump, and a chair part. a cylinder-piston unit mounted on the cylinder-piston unit and a conduit connection for the cylinder-piston unit arranged in parallel, the conduit connection at which the supply conduit and the return conduit control the cylinder-piston unit. In this type, a control valve is arranged for the cylinder/piston unit, and in this case, the hydraulic medium is throttled and supplied to the cylinder/piston unit in order to avoid sudden movement of the cylinder/piston unit.・At least one part of the piston unit (9, 17, 21, 25, 28) is a double-acting cylinder/piston unit (17, 21, 25, 28), and both of the double-acting cylinder/piston units The pressure chambers (48, 49) connect the supply conduit (31) and the return conduit (32) via the supply conduit sections (51-58) and the return conduit sections (59-66).
It is connected to a double-acting cylinder/piston unit (17, 21, 2
A control valve (81-88) is arranged in each return conduit section (59-66) for the supply conduit section (51-58) and one non-return check opening in the flow direction is arranged in each supply conduit section (51-58). Hydraulic control device for a treatment chair, characterized in that a valve (91) is arranged. 2. Each double-acting cylinder/piston unit (17, 2
1, 25, 28), one pressure chamber (49) is connected to the first supply conduit branch (76) and the other pressure chamber (48) is connected to the second supply conduit branch (76). Conduit branch (7
7), and both supply conduit branches (76, 77
2. The control device according to claim 1, wherein a control valve (92, 93) is arranged in each case upstream of the supply conduit sections (51-58) in the flow direction. 3. All piston chambers (48) of the cylinder-piston unit are connected to one supply conduit branch (77) and all piston annular chambers (49) of the cylinder-piston unit are connected to the other supply conduit branch (76).
) The control device according to claim 1 or 2, which is connected to the control device. 4. Return conduit sections (59-66) and supply conduit branches (
control valves (81 to 88; 92, 93) in
3. The control device according to any one of claims 1 to 3, wherein said valve is a two-port, two-position directional valve. 5. Control device according to claim 1, characterized in that the supply conduit (31) and the return conduit (32) are provided with a common control valve (16). 6. The control device according to claim 5, wherein the control valve (16) is a 4-port, 2-position directional switching valve. 7. In the supply conduit (31), the supply conduit sections (51 to 5
7. The control device according to claim 5, wherein at least one throttle (100, 101) is arranged upstream of the return conduit section (8) and downstream of the return conduit section in the return conduit (32). 8. The control device according to claim 7, wherein the throttle (100, 101) is integrated into the control valve (16). 9. The aperture (100, 101) is the aperture notch (133-1
9. The control device according to claim 8, wherein the control device is formed by 36). 10. The control device according to claim 9, wherein the throttle notches (133-136) are configured such that the return flow is more strongly throttled than the feed flow. 11. The control valve (16) is preloaded by a spring (33) towards the position of blocking the supply conduit (31) and the return conduit (32).
10. The control device according to any one of paragraphs 1 to 10. 12. Control device according to claim 11, wherein the control valve (16) is pre-controlled against the spring (33) by a pre-control valve (95). 13. The control device according to claim 12, wherein the front control valve (95) is a 2-port, 2-position directional switching valve. 14. The pre-control valve (95) connects the supply conduit section (35) upstream of the control valve (16) to the control conduit (96) connecting the return conduit section (36) downstream of the control valve (16). The control conduit is arranged upstream of the pre-control valve (95) and connected to the control valve (16) via a control conduit section (99), with a branch in the control conduit (96) seen in the flow direction. 14. Control device according to claim 12, characterized in that a diaphragm (102) is arranged behind the point. 15, the supply conduit section (35) located upstream of the control valve (16) in the control valve position blocking the supply conduit (31).
) is connected to a return conduit section (37, 38) extending from the cylinder-piston unit. 16, supply conduit section (35) and return conduit section (37, 3
16. Control device according to claim 15, characterized in that a restriction (34) is arranged in the passageway between the control device and the control device. 17. For movement of the upper part (3) of the treatment chair, for adjusting the inclination of the backrest (5), for running in and out of the head support (6), and/or for tilting the head support (6). Double-acting cylinder/piston units (17, 21) are used for adjustment.
, 25, 28) is used, the control device according to any one of claims 1 to 16. 18. The treatment chair according to any one of claims 1 to 17, wherein a single-acting cylinder-piston unit (9) is provided for adjusting the height of the treatment chair (1). Control device. 19. Control valves (43, 47) are arranged in each of the supply conduit section (41) and the return conduit section (37) of the cylinder-piston unit (9), claim 1
The control device according to item 8. 20. The control device according to claim 19, wherein the control valves (43, 47) are formed by two-port, two-position directional valves. 21, cylinder/piston unit (9, 17, 21,
return conduit sections (37, 59-6) connecting to
6), in which an adjustable diaphragm (46, 89) is arranged.
20. The control device according to any one of paragraphs 1 to 20. 22. The valve spool (117) of the control valve (16) is coupled to an axial control pin (118) extending through the casing (111) of the control valve (16). The control device according to any one of items 1 to 21. 23. Control device according to claim 9, characterized in that at least two control cutouts (133, 134; 135, 136) of different lengths (L, l) are provided. 24, the throttle (100, 101) is connected to the valve spool (117)
9. A control device according to claim 8, wherein the control device is arranged in a bypass (122, 123) extending in a bypass (122, 123). 25. Control blocks (105, 106) in which at least a portion of the control valves (81-88, 92, 93) arranged in the supply conduit branches (76, 77) and the return conduit sections (59-66) are preassembled; The control block is integrated into the seat (4) of the treatment chair (1).
) A control device according to any one of claims 1 to 24, which is arranged in a hollow chamber of a device.