GB1560032A - Valve for controlling the temperature of a fluid flow - Google Patents

Description

(54) A VALVE FOR CONTROLLING THE TEMPERATURE OF A FLUID rvLOW (71) We, ROBERT BOSCH G.m.b.H., a German company of Postfach 50, 7000 Stuttgart 1, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates- to a valve for controlling the temperature of a fluid flow, wherein the temperature of the fluid may be raised within the valve by providing restricted flow paths resulting in the generation of heat by dynamic pressure.

In one known valve of the above type, it is necessary to control a restricted fluid flow path in the valve by manual adjustment so as to obtain the required dynamic pressure to raise the pressure medium (especially oil) to the desired temperature. This is not only very laborious but it often happens due to inattention that the required temperature is not satisfactorily maintained.

We have now devised an improved valve of this type by which the desired temperature can be accurately maintained without the intervention of an operator. In the valves of the invention, the dynamic pressure is steplessly adjustable.

According to the invention, there is provided a valve for controlling the temperature of a fluid flow, which comprises a housing having a fluid inlet and first and second fluid outlets, the arrangement being such that fluid entering the inlet is divided in the housing into a first flow passing a restriction to said first outlet and a second flow passing a second restriction to said second outlet, the fluid becoming heated in the housing by the dynamic pressure resulting from the restricted flows, the second restricted flow during its passage to the second outlet passing in contact with a thermally responsive element mounted in the housing and being connected to a valve member within the housing upstream of the second restriction.

and wherein as the temperature of the fluid rises or falls, the said element expands - or contracts, respectively, to cause said valve member to open or close respectively against a valve seat, the dynamic pressure within the valve being reduced or increased upon opening or closing, respectively, of the valve member.

In order that the invention may be more fully understood, one embodiment will now be described, by way of example only, with reference to the accompanying drawing, in which: Figure 1 is a longitudinal 'section through a valve of the invention, and Figure 2 is a section along the line II--II in Figure 1 omitting the thermally responsive element.

Referring to the drawing, two chambers 11 and 12 which are in communication with.

one other through a stepped bore 13 of smaller diameter, are formed in a valve housing 10 at a distance from one another and in the same axial direction. The bore 11 is closed by a screw cap 14 which, however, has a passage 15 into which is screwed a connecting union 16.

A thermally responsive element 18, which extends through the entire chamber 11 and which is mounted in the stepped bore 13 by means of an extension 19, is located in a turned out portion 17 provided with a shoulder 171 in the conecting union. Figure 2 shows a section along the line II--II in Figure 1 but without the element 18. A longitudinal slot 20, through which the inner chamber 11 is connected to the passage 15, is formed on the inner end surface of the cap 14.

At the base of the chamber 11, there are.

three blind bores 22 which penetrate into the stepped bore 13. Furthermore, a longi tudinal. bore 23 extends from the chamber 11 up to the chamber 12. This bore has a comparatively small diameter, the crosssection of which can be reduced or increased by a throttle screw 24. The throttle screw is fixed in-its position with the aid of- a - nut 25. Throttling takes place by screwing in the- throttle screw 24 provided with an extension 241 to a greater or lesser depth.

The chamber 12 is closed by a screw cap 26. The cap 26 has a central bore 27 which is in alignment with the longitudinal axis of the clement 18 and in which a valve member 28 is sealingly slidingly guided. A sealing ring 29 takes care of the sealing. Due to the force of a spring 30, a knife-edge 31 on the valve member is urged on to a valve seat 32, which is made as a ring and is arranged in an annular groove 33 in the valve housing.

The spring 30 is supported on the one hand on the inner end surface of the cap 26 and on the other hand by a disc 35 which is arranged on the valve member with the aid of a snap ring 36 and wherein the outer margin of the disc forms a relatively narrow gap S with respect to the wall of the inner chamber 12.

Two bores 37, 38 enter the chamber 12 from opposite sides of the housing 10. A connecting union 39, to which is connected a line 41 leading to a delivery pump 40 is arranged in the bore 37. The pump 40 draws pressure medium out of a reservoir 43 through a suction line 42.

A.connecting union 44, in which is arranged a diagrammatically represented fixed throttle iet 45, is screwed into the bore 38.

A line 46 leads from the connecting union 44 to a reservoir 43.

A pin 47 which enters a longitudinal bore 48 in the valve member 28, is arranged at the projection 19 of the element 18. The screw-thread 50 of a valve rod 49 is screwed into the said bore. The head 511 of the screw 50 projects beyond the valve member and is secured against rotation by a nut 52.

The pressure mediumspecially oildelivered by the pump 40-especially a gear pump-arrives through the connecting union 39 in the chamber 12. A partial flow Ql of this pressure medium flows through the connecting union 44 and the throttle 45 to the reservoir 43. The remaining flow Q, flows from the chamber 12 through the gap S and the bore 23 provided with the throttle screw 24, into the chamber 11 and from there arrives through the slot 20 and the outlet union 16 at the load, for example a testing apparatus. Due to the small flow cross-section in the throttle 45 and at the throttle screw 44, there exists in the chamber 12 a high dynamic pressure. This can be adjusted to the desired value, for example 80 bars, with the aid of the throttle screw 24.

Due to the high dynamic pressure, the pressure medium is heated fairly rapidly. The flow Q, flowing to the load flows. around the element 18 which is then expanded by the prevailing heat in such a rnanner that it is supported on the one hand by the shoulder 171 and on the other hand by the pin 47 on the valve rod 49- at a lower temperature it is located in the chamber 11 with longitudinal clearance. When the pressure medium has reached its upper temperature limit, then the length of the element 18 is so greatly increased that the valve member 28 is raised completely from the valve seat 32 where upon pressure medium can flow out of the chamber 12 through the valve seat 32, the stepped bore 13 and the blind bores 22 into the chamber II.Due to the through flow cross-section becoming larger, the dynamic pressure is greatly reduced whereupon the heating of the pressure medium is reduced.

When the lower temperature limit is reached once again then the element 18 is again shortened and the spring 30 forces the valve member once again on to the valve seat 32.

The gap S between the disc 35 and the inner wall of the chamber 12 is provided in order to maintain a minimum dynamic pressure required for the generation of subpressure at the throttle 45 when the valve is fully open. The purpose of the dynamic pressure generated at the throttle 45 is to generate the required sub-pressure when testing injection pumps. In this manner, the provision of a mechanically or electrically driven sub-pressure pump can be avoided.

The screw 50 also serves to adjust the point at which the valve opens.

WHAT WE CLAIM IS:- 1. A valve for controlling the temperature of a fluid flow, which comprises a housing having a fluid inlet and first and second fluid outlets, the arrangement being such that fluid entering the inlet is divided in the housing into a first flow passing a restriction to said first outlet and a second flow passing a second restriction to said second outlet, the fluid becoming heated in the housing by the dynamic pressure resulting from the restricted flows, the second restricted flow during its passage to the second outlet passing in contact with a thermally responsive element mounted in the housing and being connected to a valve member within the housing upstream of the second restriction, and wherein as the temperature of the fluid rises or falls, the said element expands or contracts, respectively, to cause said valve member to open or close respectively against a valve seat, the dynamic pressure within the valve being reduced or increased upon opening or closing, respectively, of the valve member.

2. A valve according to claim 1, wherein the first restriction is a fixed throttle and the second restriction, connected in parallel, is an adjustable throttle.

3. A valve according to claim 1 or 2, wherein the said element acts on a valve rod connected to the valve member and is adjustable with respect thereto, to 'vary the temperature range over which the valve opens and closes 4. A valve according to any of claims 1

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (1)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   The chamber 12 is closed by a screw cap 26. The cap 26 has a central bore 27 which is in alignment with the longitudinal axis of the clement 18 and in which a valve member 28 is sealingly slidingly guided. A sealing ring 29 takes care of the sealing. Due to the force of a spring 30, a knife-edge 31 on the valve member is urged on to a valve seat 32, which is made as a ring and is arranged in an annular groove 33 in the valve housing.

   The spring 30 is supported on the one hand on the inner end surface of the cap 26 and on the other hand by a disc 35 which is arranged on the valve member with the aid of a snap ring 36 and wherein the outer margin of the disc forms a relatively narrow gap S with respect to the wall of the inner chamber 12.

   Two bores 37, 38 enter the chamber 12 from opposite sides of the housing 10. A connecting union 39, to which is connected a line 41 leading to a delivery pump 40 is arranged in the bore 37. The pump 40 draws pressure medium out of a reservoir 43 through a suction line 42.

   A.connecting union 44, in which is arranged a diagrammatically represented fixed throttle iet 45, is screwed into the bore 38.

   A line 46 leads from the connecting union 44 to a reservoir 43.

   A pin 47 which enters a longitudinal bore 48 in the valve member 28, is arranged at the projection 19 of the element 18. The screw-thread 50 of a valve rod 49 is screwed into the said bore. The head 511 of the screw 50 projects beyond the valve member and is secured against rotation by a nut 52.

   The pressure mediumspecially oildelivered by the pump 40-especially a gear pump-arrives through the connecting union 39 in the chamber 12. A partial flow Ql of this pressure medium flows through the connecting union 44 and the throttle 45 to the reservoir 43. The remaining flow Q, flows from the chamber 12 through the gap S and the bore 23 provided with the throttle screw 24, into the chamber 11 and from there arrives through the slot 20 and the outlet union 16 at the load, for example a testing apparatus. Due to the small flow cross-section in the throttle 45 and at the throttle screw 44, there exists in the chamber 12 a high dynamic pressure. This can be adjusted to the desired value, for example 80 bars, with the aid of the throttle screw 24.

   Due to the high dynamic pressure, the pressure medium is heated fairly rapidly. The flow Q, flowing to the load flows. around the element 18 which is then expanded by the prevailing heat in such a rnanner that it is supported on the one hand by the shoulder 171 and on the other hand by the pin 47 on the valve rod 49- at a lower temperature it is located in the chamber 11 with longitudinal clearance. When the pressure medium has reached its upper temperature limit, then the length of the element 18 is so greatly increased that the valve member 28 is raised completely from the valve seat 32 where upon pressure medium can flow out of the chamber 12 through the valve seat 32, the stepped bore 13 and the blind bores 22 into the chamber II.Due to the through flow cross-section becoming larger, the dynamic pressure is greatly reduced whereupon the heating of the pressure medium is reduced.

   When the lower temperature limit is reached once again then the element 18 is again shortened and the spring 30 forces the valve member once again on to the valve seat 32.

   The gap S between the disc 35 and the inner wall of the chamber 12 is provided in order to maintain a minimum dynamic pressure required for the generation of subpressure at the throttle 45 when the valve is fully open. The purpose of the dynamic pressure generated at the throttle 45 is to generate the required sub-pressure when testing injection pumps. In this manner, the provision of a mechanically or electrically driven sub-pressure pump can be avoided.

   The screw 50 also serves to adjust the point at which the valve opens.

   WHAT WE CLAIM IS:-

   1. A valve for controlling the temperature of a fluid flow, which comprises a housing having a fluid inlet and first and second fluid outlets, the arrangement being such that fluid entering the inlet is divided in the housing into a first flow passing a restriction to said first outlet and a second flow passing a second restriction to said second outlet, the fluid becoming heated in the housing by the dynamic pressure resulting from the restricted flows, the second restricted flow during its passage to the second outlet passing in contact with a thermally responsive element mounted in the housing and being connected to a valve member within the housing upstream of the second restriction, and wherein as the temperature of the fluid rises or falls, the said element expands or contracts, respectively, to cause said valve member to open or close respectively against a valve seat, the dynamic pressure within the valve being reduced or increased upon opening or closing, respectively, of the valve member.

   2. A valve according to claim 1, wherein the first restriction is a fixed throttle and the second restriction, connected in parallel, is an adjustable throttle.

   3. A valve according to claim 1 or 2, wherein the said element acts on a valve rod connected to the valve member and is adjustable with respect thereto, to 'vary the temperature range over which the valve opens and closes

   4. A valve according to any of claims 1

   to 3. wherein said element is mounted in a first chamber in the valve housing, the first chamber being connected to the second outlet and, through a bore including as the second restriction an adjustable throttle, to a second chamber, the second chamber including the valve member, and communicating with the inlet and the first outlet.

   5. A valve according to claim 4, wherein the first and second chambers are in further communication when the valve member is open.

   5. A valve according to any preceding claim wherein a spring is provided to bias the valve member onto the valve seat

   7. A valve substantially as herein described with reference to Figures 1 and 2 of the accompanying drawing.