DE102007028564A1 - Cooling system, has valve including flat springs that are operated to open valve, and manifold including rotor that operates flat springs fastened radially outside housing, where rotor operates radially inside flat springs - Google Patents

Abstract

The system (1) has a refrigerant circuit including a manifold (5) for causing distribution of a refrigerant to multiple evaporator lines (7a-7d). The manifold has a selectable valve for each evaporator line. The valve has flat springs that are operated to open the valve. The manifold has a rotor that operates the flat springs. The flat springs are fastened radially outside a housing. The rotor operates radially inside the flat springs. The rotor has an operating element that acts on the flat springs.

Description

The The invention relates to a refrigeration system with a refrigerant circuit, the multiple evaporator sections and a distribution of refrigerant on Having the evaporator sections causing distributor, wherein the Distributor for each evaporator section a controllable Valve has.

Such a cooling system is off DE 195 47 744 A1 known. The known cooling system has a single compressor and a single condenser, but two separately formed evaporator. The refrigerant flow delivered by the compressor is split into two partial flows after the condenser and before the expansion valves with the aid of a 3/2-way valve, the position of the 3/2-way valve being controlled by a control unit. With this training, however, only a division of the refrigerant flow to two evaporation sections is possible.

To be able to supply several evaporation sections is off US 5,832,744 a cooling system is known, in which the distributor between a refrigerant inlet and a plurality of refrigerant outlets has a valve, which is followed by a rotating turbine disk. The turbine disk should ensure that the refrigerant is evenly distributed to all outlets of the distributor and thus evenly to all evaporators.

One Although this type of distributor theoretically ensures uniformity Distribution of the refrigerant to the individual evaporators. However, even small differences in dimensions, which may arise, for example, during manufacture, that the refrigerant is non-uniform on the individual Evaporator is distributed. In addition, it is with such Distributors required that the individual evaporator basically the same thermal load and also the same flow resistance to have. If this is not the case, the case may occur an evaporator gets too much refrigerant, so that the refrigerant does not evaporate completely before it has passed through the evaporator. Another Evaporator connected to the same distributor can too little refrigerant, so that the evaporator the desired cooling capacity can not provide. The oversupply or the undersupply of the evaporator can lead to difficulties especially then if temperature sensors connected to the evaporators or other places the cooling system are arranged to control an expansion valve. The expansion valve may be under unfavorable circumstances be put into natural oscillations, what the capacity and the effectiveness of the cooling system continues to deteriorate.

Of the Invention is the object of a simple means desired operation of the cooling system to achieve.

These Task is in a cooling system of the aforementioned Kind solved by each valve having a leaf spring, the operation of which opens the valve, and the distributor having a leaf springs actuating the rotor.

If hereinafter referred to as a "cooling system", then this term is to be understood broadly. It particularly includes cooling systems, Freezing systems, air conditioners and heat pumps. The term "cooling system" was used for simplicity only. The evaporator sections can be arranged in different evaporators. The invention is related for reasons of simplicity explained with several evaporators. The invention is however also applicable if a vaporizer several single or groupwise having controllable evaporator sections.

Of the Distributor thus has a controllable for each evaporator section Valve, each valve having a leaf spring. A leaf spring has a surface extension. It springs due to its residual stress back to a starting position, if not through the Rotor is actuated. In this starting position she can cover an opening. As long as the opening is covered is, the valve is closed. By lifting the leaf spring of the opening can open the valve. The Using a leaf spring has the advantage of being open the valve only small forces are necessary. The drive, which sets the rotor in rotation, so does not consume too much energy. He can also use a smaller one Frame size can be formed. Through the leaf springs It is possible to customize the individual evaporator sections to control, d. H. It is possible for any vaporizer the amount supplied to refrigerant that he needs. you No need to worry about the evaporators all have the same flow resistance. It is too of minor importance if the evaporators are different Have to give off cooling. An evaporator, in which a larger cooling capacity required is, gets correspondingly more refrigerant than an evaporator, which has to provide little cooling capacity. You just have to Make sure that the valve of the evaporator, the more Refrigerant needed in one revolution of the Rotor remains open for a long time than an evaporator that requires less refrigerant.

Preferably, the leaf springs are mounted radially on the outside of a housing and the rotor acts radially inward on the leaf springs. This allows the rotor with a relatively short lever arm on the leaf springs act, so that the torque required to rotate the rotor can be kept small. Conversely, the leaf springs can have a sufficient spring length, so that they can be deformed with small forces. Both measures serve to keep the energy consumption for the drive of the rotor small. The opening covered by the leaf spring may be located at different positions. However, it is preferred if it is located between the attachment of the leaf spring to the housing and the point of attack of the rotor on the leaf spring.

Preferably the rotor has a roller-mounted actuating element on, which acts on the leaf spring. The actuator So is with a rolling bearing, such as a ball bearing, stored on the rotor. For this purpose, the rotor has a radially projecting Actuator axis on which the actuating element is arranged. The actuator can, for example be formed as a sphere or a circular disk, these elements can rotate freely on the actuator axis. If then the actuator to the respective leaf spring is passed, then there is no friction between the leaf spring and the actuator, but the Actuator rotates under the leaf spring. Again, this is a measure of energy consumption for to keep the drive of the rotor small. Furthermore this measure has the advantage that lateral forces can be kept small on the leaf spring.

Preferably is the rotor against the force of the leaf springs frontally over a rolling bearing supported on the housing. The rotor is activated each time a leaf spring is actuated Loaded axial direction. Even though these forces are only small they can eventually lead to some wear and tear. If one supports the rotor end face with a rolling bearing, then frictional forces can be kept small here become. In addition, it results in an energy-saving Work.

Preferably are the leaf springs on a common leaf spring body educated. The leaf spring body can, for example, as Ring be formed in a simple manner in the housing the distributor can be attached. For example, you can to Attach the ring Use bolts or rivets. The leaf spring body holds the individual leaf springs relative to each other in one predetermined position and also in direct association with the openings, each to be closed by the leaf springs.

Preferably the leaf springs are arranged in an inlet space, which with a Inlet port is connected. Thus the leaf springs of the Pressure in the inlet space, which is usually higher than that Pressure in the outlet of the valves, against the opening to be closed pressed. The pressure difference thus acts in the closing direction in addition to the spring force of the leaf springs. on the other hand It is possible with this training, a reverse Flow of refrigerant through the respective valves permit. For example, if the pressure in the outlet of a valve greater than the pressure at the inlet of the distributor, then the corresponding leaf spring against its normal direction of force be deformed so that refrigerant can escape. you can consciously choose this operation, for example, to passing hot gas through the evaporator sections to them defrost.

preferred meadow Each leaf spring interacts with a valve element. The leaf spring is not used directly in this embodiment to close an opening through the refrigerant from the inlet to the outlet. Rather, the leaf spring is here an auxiliary valve element, with which the actual valve element or can be controlled.

in this connection is preferred that each leaf spring has a driver, the is engaged with the valve element. So if the rotor the Leaf spring deformed contrary to their normal direction of action, then pulls the leaf spring the valve element by means of the driver of a Valve seat away and thereby opens the valve.

in this connection it is preferred that each leaf spring has at least one stiffening rib having. The stiffening rib is preferably between the driver and the point at which the rotor engages the leaf spring. This makes it possible, the leaf spring between the point the rotor and the driver so stiff that sufficient large forces can be transmitted.

Preferably the valve element has a compensation channel, that of the leaf spring is closable and by putting a pressure on both ends the valve element is compensated in the direction of movement. When on both sides of the valve element in the direction of movement of the same Pressure works, then it is easier for the leaf spring, to relocate the valve element. So you only need lower forces. This keeps the energy consumption the drive of the rotor is small.

Preferably, a first pressure application surface acting in the opening direction of the valve element is greater than a second pressure application surface acting in the closing direction. The valve element is then pilot-controlled by the leaf spring. As soon as the leaf spring releases the compensation channel, the pressure on both sides of the valve element becomes equal. Because the first Pressure application area but greater than the second pressure application surface, a force acts in the opening direction, which is greater than a force in the closing direction. This force difference then moves the valve member away from its valve seat and opens the valve.

In An alternative embodiment may be provided that the valve element has two equal pressure application surfaces, of which a first in the opening direction and a second acts in the closing direction. The two pressure application surfaces do not have to be the same size in the mathematical sense. It is sufficient if the forces acting on the valve element are about balanced. In this case one must over the Leaf spring only small forces apply to the valve to open.

Preferably is a pressure chamber from the first pressure application surface is limited, via a throttle path with an output connected to the valve. This throttle path can between the valve element and a guide of the valve element may be formed. He can also be formed simply by the fact that the Ventilele ment led with a certain play in the guidance is. If then the compensation channel closed by the leaf spring is, then no new refrigerant can flow into the pressure chamber. However, the refrigerant located there passes through the throttle path into the outlet, so that the pressure drops. The power which the pressure in the inlet space exerts on the valve element, then leads together with the force of the leaf spring to a closing movement of the valve element.

Preferably the rotor is connected to a motor and there are means for detecting the angular position of the rotor provided. This is a controlled Control of each valve possible. The engine can preferably be designed as a stepper motor. This makes it possible to control the rotor in predetermined angular positions, so that he For example, the largest possible degree of opening a Adjust valve.

in this connection it is preferred that the means comprise a magnet arrangement. With Help a magnet assembly can be position signals from the distributor transferred out without a corresponding passage opening would be necessary. This is a simple measure to keep the distributor tight.

The Invention will be described below with reference to preferred embodiments described in conjunction with the drawing. Herein show:

1 a schematic representation of a cooling system with multiple evaporators,

2 a first embodiment of a distributor in section,

3 a part of the distributor in a sectional perspective view,

4 a second embodiment of the distributor partially in section,

5 an enlarged view of the detail V after 4 .

6 another section of the distributor after 4 in an enlarged view,

7 a perspective view of a leaf spring body,

8th a leaf spring in an enlarged view,

9 a first embodiment of a valve element and

10 a second embodiment of a valve element.

1 shows a schematic representation of a cooling system 1 in which a compressor 2 , a capacitor 3 , a collector 4 , a distributor 5 and an evaporator arrangement 6 with several parallel evaporators 7a - 7d are connected together in a circuit. The evaporator arrangement 6 may also have a single nen evaporator having a plurality of evaporator sections to be controlled individually or in groups. It is also possible the evaporator arrangement 6 provide with a plurality of evaporators, of which at least one has a plurality of evaporator sections.

In a conventional manner, liquid refrigerant evaporates in the evaporators 7a - 7d , is through the compressor 2 compressed, in the condenser 3 liquefied and in the collector 4 collected. The distributor 5 is intended to apply the liquid refrigerant to the individual evaporator 7a - 7d to distribute.

At the exit of each evaporator 7a - 7d is a temperature sensor 8a - 8d arranged. The temperature sensor 8a - 8d determines the temperature of the evaporator 7a - 7d leaving the refrigerant. This temperature information is sent to a control unit 9 passed on, depending on the temperature signals of the temperature sensors 8a - 8d the distributor 5 controls.

The 2 and 3 show a first embodiment of the distributor 5 , The distributor 5 has a housing 10 on, with a drive 11 connected is. The drive 11 is designed, for example, as a stepper motor, via lines 12 Sig nale of the control device 9 receives. The drive 11 has an output shaft 13 on, rotatably with a rotor 14 connected in the housing 10 is stored.

The housing 10 has an inlet 15 and several outlets 16 on. The inlet communicates with an inlet space 17 in connection. The outlets 16 each lead via an outlet channel 18 in the inlet room 17 , However, the outlet channels 18 each by a leaf spring 19 locked. The leaf springs 19 lie under an internal bias on a bottom plate 20 of the housing. Because the pressure in the inlet space 17 normally higher than the pressure in the outlets 16 , The pressure difference acts in the closing direction on the leaf springs 19 ,

The leaf springs 19 are with their radially outer end to a ring 21 attached. Preferably, the leaf springs 19 integral with the ring 21 educated. One from the leaf springs 19 and the ring 21 trained leaf spring body can be made for example by punching. The ring 21 has several tabs 22 on, which protrude radially inward. Through the tabs 22 each is a rivet 23 or a corresponding bolt passed to the ring 21 with the leaf springs 19 at the bottom plate 20 set.

The rotor 14 is on its front over a ball 24 at the bottom plate 20 supported. The bottom plate 20 has a recess for this purpose 25 on, the front end of the rotor 14 receives. The rotor 14 has a radially projecting projection 26 on, which acts as an actuator. How out 3 can be seen, the projection acts in the illustrated position of the rotor on a leaf spring 19 ' and lifts them from the mouth of an exhaust duct 18 in the inlet room 17 off, leaving refrigerant from the inlet space 17 through the outlet channel 18 can flow out. If the rotor 14 is rotated further, then puts the leaf spring 19 again flat to the bottom plate 20 on, so that the corresponding exhaust duct 18 is closed.

The rotor 14 is also connected to a disk 27 in an opening 28 wearing a magnet not shown. The magnet acts through the wall of the housing 10 through, so the position of the disc 27 can always be detected from the outside. The information about the position of rotation with the rotor 14 connected disc 27 is an information about the position of the projection 26 , so that you always know exactly which valve is currently open, ie which of the leaf springs 19 . 19 ' straight from the mouth of the corresponding outlet channel 18 has lifted off. This mouth forms a valve seat 29 , A combination of leaf spring 19 and valve seat 29 is also called "valve 30 " designated.

In the circumferential direction adjacent leaf springs 19 have a distance that is greater than the extension of the projection 26 in the circumferential direction. Accordingly, it is possible to use the rotor 14 to turn so that none of the valves 30 is open.

The distribution of the refrigerant on the individual evaporator sections 7a - 7d Now takes place in that the rotor 14 through the drive 11 is turned. For this purpose, the rotor 14 turned into a position in which he has a leaf spring 19 . 19 ' from the valve seat 29 takes off. Over the period of time in which the leaf spring 19 . 19 ' from the valve seat 29 is lifted, the amount of refrigerant can be determined in the corresponding evaporator section 7a . 7d flows. As soon as enough refrigerant in the ent speaking evaporator section 7a - 7d has flowed, the rotor is rotated further to the next valve 30 to open.

Should a valve 30 can not be opened, then you can either the rotor 14 rotate relatively quickly over this valve, leaving the lead 26 the valve 30 opens only very briefly. Due to the inertia of the evaporator sections, the small amount of refrigerant that then enters the evaporator section plays 7a - 7d arrived, practically no role. You can also change the direction of rotation of the rotor 14 turn around so that the lead 26 the corresponding valve 30 not open at all.

In the embodiment of the 2 and 3 become the leaf springs 19 . 19 ' used directly to prevent the passage of refrigerant from the inlet space 17 in the outlet channels 18 to control.

The 4 to 10 show a modified embodiment in which the leaf springs 19 be used as auxiliary elements. Like mutually corresponding elements are denoted by the same reference numerals as in FIGS 2 and 3 Mistake.

The housing 10 has a central inlet 15 and radially arranged outlets 16 on. The valves 30 are arranged distributed uniformly in the circumferential direction.

Every valve 30 has a valve element 31 on, approximately parallel to the axis of rotation of the rotor 14 is relocatable. In the in 4 shown position is the valve element 31 at the valve seat 29 on, allowing a passage from the inlet space 17 to the outlet channels 18 is closed.

Each valve element 31 limits a pressure chamber 32 together with the housing 10 , A compensation channel 33 passes through the valve element 31 lengthwise. The equalization channel 33 flows into the inlet space 17 with a mouth 34 , where the mouth 34 through the leaf spring 19 is closed.

The valve element 31 points in his the pressure room 32 opposite end of a cone-shaped projection 35 with an undercut 36 on. The estuary 34 is in the middle of the lead 35 arranged.

Like from the 7 and 8th can be seen, each leaf spring 19 a driver 37 on, behind the undercut 36 attacks, with a small game. So if the leaf spring 19 is raised, then first the mouth 34 Released, allowing refrigerant gas from the inlet space 17 in the compensation channel 33 and thus in the pressure room 32 can flow. Upon further lifting of the leaf spring 19 takes the driver 37 the cone-shaped projection 35 with and thereby pulls the valve element 31 parallel to the axis of rotation of the rotor 14 from the valve seat 29 path. This will create a path from the inlet space 17 to the outlet 16 the corresponding valve 30 Approved.

The force that the leaf springs 19 at this opening of the valve 30 on the valve element 31 must exercise is relatively small, because the on both sides of the valve element 31 acting pressures due to the equalization channel 33 are the same size. Further details will be provided below 9 and 10 discussed.

The rotor 14 has an actuating element in this embodiment 38 on, that about a rolling bearing 39 on a radial from the rotor 14 projecting actuator axis 40 is stored. This actuator 38 So it can be rotated when using a leaf spring 19 engages. This causes friction forces between the leaf spring 19 and the actuator 38 can be kept very small. There is virtually no risk that too much lateral forces on the leaf spring 19 act, leaving the leaf spring 19 even after a long operation very close to the mouth 34 of the compensation channel 33 remains aligned.

The leaf spring 19 has in one area 41 in which the actuator 38 on the leaf spring 19 acts, two stiffening ribs 42 that are simply formed by that material from the leaf spring 19 has been bent upwards by about 90 °. This will make the leaf spring 19 between the point where the actuator 38 on the leaf spring 19 attacks, and the driver 37 relatively stiff, allowing the force from the actuator 38 practically directly on the driver 37 can be transferred.

For the formation of the valve element 31 There are now several possibilities in the 9 and 10 are shown. 9 shows an embodiment in which the valve element 31 in the pressure room 32 a first pressure attack surface 43 which is larger than a second pressure application surface 44 in the inlet room 17 , The first pressure application area 43 has a size A1. The second pressure application area 44 has a size A2. If A1 is greater than A2 and due to the equalization channel 33 on both pressure attack surfaces 43 . 44 the same pressures act, then a force is the valve element 31 from the valve seat 29 moved away, greater than a force that the valve element 31 to the valve seat 29 moved. So if the leaf spring 19 from the mouth 34 takes off and through the compensation channel 33 a pressure equalization takes place, then the valve element 31 from the valve seat 29 lifted. Between the valve element 31 , in the present case via a piston ring 45 in a guided tour 46 is guided, and the housing 10 However, there is no tightness, so that refrigerant from the pressure chamber 32 via a throttle section in the outlet 16 can flow out. So if the mouth 34 through the leaf spring 19 is closed again, the pressure in the pressure chamber decreases 32 so that the valve 30 closes again.

10 shows a modified embodiment in which the two pressure application surfaces 43 . 44 are about the same size, ie A1 = A2.

If in this case the smooth spring 19 from the mouth 34 of the compensation channel 33 takes off, then takes place only a moderate compensation over the valve element 31 so that the leaf spring 19 the valve element 31 with the help of the driver 37 from the valve seat 29 withdraws. But there are virtually no or only relatively small external forces on the valve element 31 To act, is to perform such Derar tige movement with relatively little force. The distributor can therefore be operated very energy-efficient.

In both embodiments, the valve 30 be opened by refrigerant, namely, when the pressure of the refrigerant at the outlet 16 larger than in the inlet room 17 , The refrigerant pressure in this case only has to be the force of the leaf spring 19 overcome.

Also in the embodiment, in the 2 and 3 is shown, you can an actuator 38 use, which is roller-mounted. Also in the embodiment of 4 to 10 you can use the rotor with a ball bearing in the housing 10 support.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19547744 A1 [0002]
• US 5832744 [0003]

Claims (15)

Cooling system with a refrigerant circuit which has a plurality of evaporator sections and a distributor which effects a distribution of refrigerant on the evaporator section, the distributor having a controllable valve for each evaporator section, characterized in that each valve ( 30 ) a leaf spring ( 19 . 19 ' ) whose actuation the valve ( 30 ), and the distributor ( 5 ) one the leaf springs ( 19 . 19 ' ) actuating rotor ( 14 ) having. Cooling system according to claim 1, characterized in that the leaf springs ( 19 . 19 ' ) radially on the outside of a housing 10 are fixed and the rotor ( 14 ) radially inward on the leaf springs ( 19 . 19 ' ) acts. Cooling system according to claim 1 or 2, characterized in that the rotor ( 14 ) a roller-mounted actuating element ( 38 ), which on the leaf springs ( 19 . 19 ' ) acts. Cooling system according to one of claims 1 to 3, characterized in that the rotor ( 14 ) against the force of the leaf springs ( 19 . 19 ' ) frontally via a rolling bearing ( 39 ) on the housing ( 10 ) is supported. Cooling system according to one of claims 1 to 4, characterized in that the leaf springs ( 19 . 19 ' ) on a common leaf spring body ( 21 ) are formed. Cooling system according to one of claims 1 to 5, characterized in that the leaf springs ( 19 . 19 ' ) in an inlet space ( 17 ) arranged with an inlet port ( 15 ) connected is. Cooling system according to one of claims 1 to 6, characterized in that each leaf spring ( 19 ) with a valve element ( 31 ) cooperates. Cooling system according to claim 7, characterized in that each leaf spring ( 19 ) a driver ( 37 ), which is connected to the valve element ( 31 ) is engaged. Cooling system according to claim 7 or 8, characterized in that each leaf spring ( 19 ) at least one stiffening rib ( 42 ) having. Cooling system according to one of claims 7 to 9, characterized in that the valve element ( 31 ) has a compensation channel, which of the leaf spring ( 19 ) is closable and by the pressure on both ends of the valve element in the direction of movement can be compensated. Cooling system according to claim 10, characterized in that in the opening direction of the valve element ( 31 ) acting first pressure application surface ( 43 ) is greater than a second pressure application surface acting in the closing direction ( 44 ). Cooling system according to claim 10, characterized in that the valve element ( 31 ) two equal pressure application surfaces ( 43 . 44 ), of which a first acts in the opening direction and a second in the closing direction. Cooling system according to claim 11 or 12, characterized in that a pressure chamber ( 32 ) coming from the first pressure application surface ( 43 ) is limited via a throttle path ( 45 . 46 ) with an output ( 16 ) of the valve ( 30 ) connected is. Cooling system according to one of claims 1 to 13, characterized in that the rotor ( 14 ) with a motor ( 11 ) and means ( 27 . 28 ) for detecting the angular position of the rotor ( 14 ) are provided. Cooling system according to claim 14, characterized in that the means ( 27 . 28 ) have a magnet arrangement.