DK173985B1 - Pressure regulator for a portable agricultural application device - Google Patents

Description

DK 173985 B1

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a pressure regulator for a portable agricultural dispensing device for dispensing liquid from a storage tank and having a flow space located in a regulator housing, from which a dispensing channel for the dispensing device, a return channel for the storage tank, and a bypass channel for a stirrer, both the return channel and the bypass channel are each provided with an adjustable choke point.

A pressure regulator for an agricultural dispensing device is known from German Gebrauchsmuster 93 01 935. I. The pressure regulator has a housing in which a distributor chamber is arranged. From an upper side, a filter insert is inserted in this distributor chamber for filtering the liquid flow flowing through the distributor chamber. At the inlet side, the distributor chamber is connected to a pressure line supplied from a liquid storage tank. At the output side, a dispensing duct is branched from the distributor chamber, whereby the liquid stream supplied to the dispensing duct is filtered into the distributor chamber through the filter device. The dispensing duct leads to the dispensing device, which is preferably provided with spray nozzles or the like. In addition, at the output side, a return channel is joined to the distribution chamber, the flow rate of which is regulated by means of a control device. The reflux channel is connected to a return line to the storage tank, whereby the reflux channel can alternatively be fed to a main reflux line or a stirring line to operate a stirrer in the storage tank. However, especially with relatively low spray pressure in the dispenser, the operation of the agitator by means of the branched reflux flow is no longer possible.

25 The unpublished German utility model application G 94 09 680.5 discloses a pressure regulator for a portable agricultural application device in which the pressure regulator housing is provided with a filter device insertable from above in a flow room. From the flow room, an application channel is branched to the spraying nozzles of the application device. From an area of the flow chamber with increased static pressure, a reflux duct, 2 DK 173985 B1, branching off into a reflux line for the storage tank for the liquid to be applied is branched. In addition, a bypass channel is provided from the region of the flow chamber with increased static pressure, which leads to a stirrer pipeline leading to a stirrer in the storage tank. The flow rates in the reflux duct as well as in the bypass duct are controllable by means of throttle devices, each throttle device being continuously adjustable by means of a control device. The pressure in the delivery duct is simultaneously regulated.

In the provision of the bypass duct leading to the agitator, the supply of liquid to the agitator is independent of the pressure in the reflux duct, whereby, in connection with an elevated static pressure in a specific area of the flow chamber, even at low spray pressure an influence of the agitator is ensured. The flow chamber has an area of elevated static pressure as well as an area of less static pressure.

The object of the invention is to provide a pressure regulator of the type mentioned initially, which has a simple structure and, in addition, even at small spray pressures, allows a sensitive control of the spray pressure in connection with the operation of the agitator.

The object is thereby achieved that the two choke points are jointly controllable by means of a common adjusting device, whereby the throttle position of the bypass channel is provided with a throttle function in relation to the return channel in the opening direction. Thereby, a single adjusting device is sufficient to control both the flow in the reflux channel and in the bypass channel. Thereby, in relation to each other, temporarily set throttle functions are obtained by means of which one of the two throttle sites follows the other, whereby, at already full flow rate by means of one of the two channels, a further spray pressure reduction in the delivery channel can also be obtained. By providing only a common adjusting device 30, compared to the pressure regulator described in the prior art controller, a setting device is obtained, whereby a simplified structure with unchanged functional possibilities is obtained.

In one embodiment of the invention, the adjusting device for each throttle location has a throttle slider which is rigidly connected to one common linear adjustment, whereby one throttle slider over a specified length approximately equal to the stroke length of the other throttle slider closes tightly with it. associated throttle seat. In a further embodiment of the invention, the two throttle sliders are configured as different axial regions of an infinitely adjustable regulating piston which is arranged horizontally in the pressure regulator housing. Thereby, the regulating piston takes on a dual function, which partly controls the flow through the bypass channel and partly through the flow through the return channel. In a further embodiment of the invention, in the region at each outlet of the reflux duct and the bypass duct of the storage tank, a three-way valve is in communication with the two outlets, which three-way valve is infinitely adjustable. In this way it is possible to divide continuously the amount of stirring between the agitator and the reflux to the dish. Such stepless splitting is especially appropriate when the stirring effect becomes too intense.

20

The object of the invention is achieved in that in a flow room area arranged in the flow direction prior to a distribution chamber a tuning device is provided for increasing the static pressure of the liquid flow from which the bypass channel leading to the agitator is branched. As a result of the branching of the bypass duct before the distributor chamber, a supply of liquid to the agitator is independent of the pressure in the reflux duct. By means of the tuning device, even at low spray pressure, a sufficient static pressure is obtained in front of the distributor chamber, so that an influence on the agitator is ensured. In this way it is also possible to stir the liquid in the storage tank even with low spray pressure.

In a further embodiment of the invention, a throttle aperture arranged at the junction between the flow room area and the distributor chamber is provided. This is a particularly simple and inexpensive design, yet at the same time provides sufficient functionality.

In a further embodiment of the invention, the return channel and bypass channel are guided in the controller housing in mutually parallel planes. In this way, despite the separately led reflux and pipeline lines, a compact housing is obtained.

Further advantages and characteristics of the invention will become apparent from the subclaims and the following description of a preferred embodiment of the invention shown by the drawing.

Figure 1 shows a longitudinal section of an embodiment of a pressure regulator according to the invention, in which the delivery channel leading to the dispensing device is not shown, whereby a bypass channel leading to a stirrer as well as a return channel leading to a storage tank is provided. .

Fig. 2 shows a section through the pressure regulator according to fig. 1 along the section plane II-II in FIG. 1, and

Figure 3 is a side view of a housing portion of the pressure regulator as shown in FIG. 1 in the direction of arrow III, whereby the housing part with the filter insert is removed.

A pressure regulator as shown in Figures 1 to 3 is provided for regulating the spray pressure of a spray conveyor transportable by means of a tractor which produces a spray liquid such as manure or pesticides. The spray liquid is stored in a storage tank located on the tractor. The required spray pressure for the pressure regulator is controlled by a pump dependent on the tractor driving speed, which is located on the pressure input side between the pressure regulator and the storage tank. In order to be able to stir the spray liquid in the storage tank and thus also maintain a homogeneous mixture for a longer period of time, a stirrer is arranged in the storage tank which enters spray liquid from the pressure regulator into the storage tank to form a stirring process, which spray liquid is not required for the spray bar spray process. The pressure regulator has a housing consisting of four housing parts 1 to 4. A housing part 1 has a flow chamber 6 extending over the same height of the housing, which flow chamber at the inlet side is provided with a connection plug 5 for a pump line supplied from the pump. By inserting a filter insert part 10, 6 areas of different 10 static pressures are obtained in the flow chamber. The filter insert part 10 is inserted from above into the housing part and corresponds essentially to a filter insert known from the German utility model G 93 01 935.1. The filter insert part 10 has a filter 1 in a lower region and divides by means of a special design the flow chamber 6 into two regions with different static pressures. Between a distributor chamber 8 forming a central region of the flow space 6 and a lower area adjacent to the connection nozzle 5, the filter housing insert has at its outer circumference several throttle bores 12 which form a throttle aperture, by means of which, relative to the distribution chamber 8 in the lower region. of the flow chamber 6 an increased static pressure is formed. The core of the filter insert part 10 is formed axially so that the applied pump flow P in the flow space 6 is divided into a dispensing stream A into a non-dispensing channel which communicates with the spray beam and in an axially flowing partial flow. The dispensing stream A is branched from the distributor chamber 8, the axially throttled flow-through partial flow in the lower area 7 of the flow chamber 6 flows coaxially upwardly and is radially laterally outwardly removed through radial reflux ports 9 in the filter housing insert 10 in the filter housing insert 10. 13 (bypass stream 10). A reflux stream R, like the flow stream A in the direction of flow after throttle bores 12, is branched out from the branching chamber 8. To the housing part 30, a housing part 2 is laterally connected, in which both the bypass channel 13 and the reflux channel 30 for the reflux stream R are continued. The bypass duct 13 as well as the trailing duct 30 extend in parallel parallel planes. The reflux channel 30 for the reflux stream R is in FIG. in front of the drawing plane, why the arrows for the reflux stream R are shown only in dotted line.

5 The flow rate in the bypass duct 13 as well as the flow rate in the reflux duct 30 is controlled by a common regulating plunger 14, which is infinitely controllable by means of an electric motor 25 arranged in a housing part 3 and a corresponding spindle drive. In relation to the vertically arranged filter insert part 10, the control piston 14 is arranged horizontally 10 in the housing part 2 and also horizontally linearly adjustable. The two throttle openings 16 and 29 of the bypass duct 13 and the return duct 30 are coaxially spaced relative to each other, whereby the throttle opening 16 belongs to a throttle region 15 of the regulating piston 14, and to which the throttle opening 29 belongs The throttle region 18 serving as throttle slider 18 of the regulating piston 14. The throttle opening 16 is in relation to the axis of adjustment of the regulating piston 14 at axial distance from the throttle opening 29, whereby the throttle opening 16 is axially located at a greater distance from the free end from the regulating piston 14 than from the throttle opening 29. The diameter of the throttle opening 16 is larger than the diameter of the throttle opening 29. The throttle region 15 of the control piston 14, which in a closed state ends tightly with the throttle opening 16 of the bypass channel 13, extends tapered towards the free end of the control piston 14. On the tapered throttle region 15, a smaller diameter cylindrical closure region 17 joins the end of the regulating piston 14. To the free end of the regulating piston 14 joins the cylindrical closure region 17 a rounded and obliquely cut throttle region 18. The throttle seat 16 of the throttle opening 16 thus cooperates with the tapered tapered throttle region 15 that bypasses the regulating piston 14 in the opening direction (in Fig. 1). will be opened and the bypass flow B in the direction of arrow B can flow to a stirred housing outlet 23.1 flow direction behind the throttle region 15 of the regulating piston 14 7, the bypass flow B flows through a bypass opening 20. The throttle seat anchored in the housing the region of the throttle opening 29 has an axial length increased relative to the throttle opening 16 of the throttle opening 16. The distance from the throttle seat 16 of the throttle opening 16 to the throttle seat 29 is less than the distance between the two throttle portions 15 and 18 of the regulator piston 14, whereby the throttle seat 29 throttle seat is adapted to the diameter of the cylindrical region of the regulator piston 14 in is thereby open in this orifice region towards the regulating piston 14. The orifice region 10 19 extends in Figure 1 vertically with respect to the drawing plan from the front to the rear.

As soon as the control piston is displaced by means of the electric motor 25 from the one shown in FIG. 1 and 2, in the opening direction, a bypass stream B flows through the annulus between the throttle region 15 and the throttle seat of the throttle region 16, so that the bypass stream B is passed through the throttle opening 20 and is fed to the agitator. However, in this opening position, the throttle opening 29 is still closed by means of the cylindrical region of the control piston 14. The control piston 14 is now further displaced in the opening direction 20, the area 17 reaches approximately to the axial height of the throttle opening of the throttle opening, thereby generally releasing the orifice area 19 and thus the throttle opening 29 (see Fig. 2). Thereby it is possible for the reflux stream R to pass through the throttle opening 29 and through the throttle opening 21 to be passed to the reflux port 22 of the housing part 2.

25

In this mode of operation of the regulator, the same benefits are obtained as with the pressure regulator according to G 94 09 680.5. However, in relation to this pressure regulator, the pressure regulator according to the invention lacks a control element for manual operation. Thereby, an operator need not make a preset to avoid setting errors.

8 DK 173985 B1

It is further advantageous that the bypass must first be fully opened before the pressure via the reflux line (reflux flow R) can be lowered again. The more the piston is opened to lower the spray pressure via the return line, ie. the more liquid flowing through the throttle bore 12, the more the static pressure which affects the bypass increases. Part of the pressure loss is again compensated by the down regulation of the return piston, so that in every situation a maximum stirring capacity is available.

The regulating piston 14, along its axial extent 10, forms two different choke points, a dual function. Its sloping tip of the throttle region 18 enables a largely linear flow characteristic. The control piston 14 thereby enables a sensitive control. The throttle region 18 extends in relation to the throttle region 15 in its throttle function in the opening direction in time, thereby also allowing a further spray pressure reduction when the back pressure from the agitator at the housing output 23 becomes too great. The reflux port 22 directly connects the reflux duct 30 with the storage tank.

In the flow direction behind the throttle openings 20, 21, the bypass channel 20 13 and the return channel 30 extend parallel to each other and approximately vertically downward. In this region, the bypass channel 13 and the return channel 30 are connected to each other by means of a cylindrical passageway, which passage has a horizontal axis parallel to the control piston 14. The passage is closed by means of a three-way valve 24 which, by means of an additional electric motor 26 parallel to the control piston 14, is continuously adjustable in a horizontal direction. The three-way valve in its construction corresponds essentially to the three-way valve already described in G 93 01 935.1.

By means of the three-way valve 24, which is in communication with both the reflux duct 30 and the bypass duct 13, it is possible with a stepless control to divide the bypass flow optionally between the reflux of the storage tank and the reflux line of the agitator. This is particularly advantageous when an excessive stirring effect occurs due to an increased flow pressure in the bypass channel.

The bypass duct 13 is provided immediately adjacent to the filter insert portion 10 with a safety valve 27 which is closed by a pressure spring 28.

By excessive overpressure in the bypass duct 13, this safety valve 27 is opened, thereby releasing a flow duct directly into the reflux duct to the storage tank, whereby the flow duct is laterally passed through the throttle area 18 formed by throttle opening 29, the cylindrical region 17 and the regulating piston 14 throttle location (fig. 2). An overpressure in the bypass duct 13 and a resultant opening of the safety valve 27 thereby, regardless of the setting of the regulating piston 14, always causes a sufficient pressure drop.

15

Claims (9)

10 DK 173985 B1 P a t e n t k r a v: 1. A pressure regulator for a portable agricultural dispensing device for dispensing liquid from a storage tank and having a flow space arranged in a regulator housing, from which a dispensing channel for the dispensing device, a return channel for the storage tank and a bypass channel for a stirrer in the storage tank, the return channel as the bypass channel each is provided with an adjustable choke point, characterized in that two choke points (15, 16; 18, 29) are jointly controllable by means of a common setting device (14, 25), whereby the bypass channel (13 ) throttle location (15, 16) is provided with a throttle position (18, 29) in the opening direction prior to throttle operation relative to the return channel (30). Pressure regulator according to claim 1, k characterized in that the adjusting device (14, 25) for each throttle location (15, 16; 18, 29) each has a throttle slider (15,18) which is rigidly connected to a common linear setting. one another, whereby one throttle slider (18) moves in a direction of movement over a certain length approximately equal to the stroke length of the other throttle slider (15), closely closing with the associated throttle seat (29). Pressure regulator according to claim 2, characterized in that the two throttle sliders (15, 18) are arranged on a common setting axis and that one throttle slider (18) in the opening direction has a closed area (17) which is provided for a length of 25 with a defined axial stroke volume of a constant cross-section, said closure region being spaced at an axial distance to the second throttle slider approximately equal to the spacing between the two throttle seats (29, 16). Pressure regulator according to claim 3, characterized in that the two throttle sliders (15, 18) are formed as different axial regions of an infinitely adjustable regulating piston (14) which is arranged horizontally in the regulating housing (1, 2). , 3, 4). Pressure regulator according to any one of the preceding claims, characterized in that a three-way valve (24) is arranged in the area at each outlet (23, 22) of the reflux duct (13) and the bypass duct (30) of the storage tank. , which is operatively connected to the two outlets (22, 23), which three-way valve is infinitely adjustable. Pressure regulator according to claim 5, characterized in that the three-way valve (24) setting axis is arranged parallel to the control piston (14) setting axis. Pressure regulator according to claim 1, k characterized in that in the flow direction region (6) arranged in a flow direction (6), a padding device (12) is provided for increasing the static pressure of the liquid flow and that from this flow space area ( 6), a bypass channel (13) is delimited leading to the agitator. Pressure regulator according to claim 7, k characterized in that a throttle aperture (12) is provided as a tuning device in the transition between the flow space area (6) and the distributor chamber (8). Pressure regulator according to any one of the preceding claims, characterized in that the reflux duct (30) and the bypass duct (13) are routed in the regulator housing (1 to 4) in mutually parallel planes.