Pulsating flow generator

Abstract

This invention provides a pulsating flow generator that can efficiently pulsate the pressure of a liquid, has a simple configuration, and is highly durable. [Solution] The problem of the present invention is solved in a pulsating flow generator 1 provided in a flow path between a liquid supply means and a nozzle that sprays liquid, which causes the flow rate of the liquid sprayed from the nozzle to change in accordance with the pressure pulsation by causing the pressure of the liquid flowing through the flow path to pulsate. The pulsating flow generator 1 comprises a main body 2 having a main flow path through which liquid flows from the liquid supply means toward the nozzle, and a pulsation generating unit 4 having a volume fluctuation unit that alternately absorbs and releases the liquid flowing through the main flow path via a branch path to which the flow path branches off, thereby increasing and decreasing the internal volume. The pulsation generating unit 4 solves the problem by alternately repeating a filling step of absorbing liquid from the main flow path and a release step of releasing the absorbed liquid into the main flow path when liquid is supplied at the input liquid pressure, thereby superimposing the fluctuating volume fluctuation pressure on the input liquid pressure of the liquid and causing the liquid pressure to pulsate.

Description

Technical Field

[0001] The present invention mainly relates to a pulsating flow generator suitable for use in a cleaning device such as a warm water cleaning toilet seat. It is provided in a flow path between a liquid supply means for supplying liquid and a nozzle for injecting the supplied liquid from an open end, and by pulsating the pressure of the liquid flowing through the flow path, it relates to a pulsating flow generator that gives a change corresponding to the pressure pulsation to the flow rate of the liquid injected from the nozzle.

Background Art

[0002] Conventionally, in a cleaning device such as a warm water cleaning toilet seat, by periodically pulsating the pressure of the water injected from a nozzle, the amount of water injected with pressure fluctuations is changed. For example, by changing the injected water into water droplets, etc., a pulsating flow generator is known that can maintain or increase the cleaning power against the cleaning target while suppressing the amount of water used (see Patent Document 1 and Patent Document 2, etc.).

[0003] As shown in FIG. 5, in a conventional pulsating flow generator, water supplied into the flow path 200 from the suction port 100 at the inlet pressure is sent from the discharge port 300 toward the nozzle. During this time, the plunger 400 arranged in the flow path 200 is alternately moved along the flow path in the forward and reverse directions of the water flow (moved up and down in FIG. 5) by the magnetic force generated by exciting the externally fitted coil and the elastic force of the spring, thereby pulsating the water pressure. That is, in a conventional pulsating flow generator, when the plunger 400 moves from the suction port 100 side toward the discharge port 300 side, the water pressure is increased by applying a plunger pressure to the water by pushing out the water toward the nozzle with the front end face on the discharge port 300 side of the plunger 400. Conversely, when the plunger 400 moves from the discharge port 300 side toward the suction port 100 side, the space on the discharge port 300 side of the plunger 400 is filled with water depressurized while passing water through the through hole 500, and by repeating this process, the water pressure is pulsated.

[0004] However, in conventional configurations, as shown in Figure 5, when the plunger 400 moves from the discharge port 300 side to the intake port 100 side, a through hole 500 must be provided in the plunger 400 to allow water to pass through to the front end surface of the plunger 400. Consequently, when the plunger 400 moves again towards the discharge port 300 side, water escapes through this through hole 500 to the intake port 100 side of the plunger 400, making it impossible to efficiently apply pressure to the water at the front end surface of the plunger 400 on the discharge port 300 side. Therefore, measures have been taken to prevent water from escaping when applying pressure to the water by providing a check valve 600 or the like in the through hole 500, but this complicates the structure and presents problems with the durability of the check valve, shortening the overall service life and maintenance period of the pulsating flow generator. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2001-304101 [Patent Document 2] Japanese Patent Publication No. 2001-81837 [Overview of the project] [Problems that the invention aims to solve]

[0006] Conventional pulsating flow generators have a plunger positioned in a flow path leading from a liquid supply means to a nozzle. By moving the plunger toward the nozzle, the volume on the front end face side in the direction of the plunger's movement (the volume downstream from the front end face of the plunger to the nozzle) is compressed, increasing the pressure of the liquid on the front end face side of the plunger and causing the liquid to be ejected from the nozzle. However, when returning the plunger to its original position, the liquid must pass through a through-hole provided in the plunger to supply liquid to the front end face side. Therefore, the plunger in conventional pulsating flow generators is forced to perform two contradictory roles: to prevent liquid from escaping as much as possible when the plunger moves downstream, and conversely, to allow as much liquid as possible to pass through when the plunger returns upstream. This configuration inherently has a contradiction.

[0007] The present invention aims to resolve the contradictory configurations of conventional pulsating flow generators, provide a pulsating flow generator that can efficiently pulsate liquid pressure, has a simple configuration, and is highly durable. [Means for solving the problem]

[0008] The problem of the present invention is solved by the configuration of the feature part described in claim 1. That is, according to a first aspect of the present invention, a pulsating flow generating device is provided in a flow path between a liquid supply means that supplies liquid at an inlet pressure and a nozzle that sprays the supplied liquid from an open end, and by pulsating the pressure of the liquid flowing through the flow path, the flow rate of the liquid sprayed from the nozzle changes in accordance with the pressure pulsation, and the device has a main body with a main flow path through which liquid flows from the liquid supply means toward the nozzle, and a pulsation generating unit with a volume fluctuation unit that alternately absorbs and releases the liquid flowing through the main flow path by increasing or decreasing the internal volume via a branch path to which the flow path branches off from the main flow path, and the pulsation generating unit alternately repeats a filling step in which the internal volume of the volume fluctuation unit is increased to absorb liquid from the main flow path and a release step in which the internal volume of the volume fluctuation unit is decreased to release liquid into the main flow path, thereby superimposing the fluctuating volume fluctuation pressure on the inlet pressure of the liquid and causing the liquid pressure to pulsate.

[0009] The inventors of this invention have re-examined the contradictory configuration of the plunger in conventional pulsating flow generators and have created the present invention by branching the flow path from the main channel through which liquid flows from the liquid supply means to the nozzle into a branch channel, and by providing a volume fluctuation section on the branch channel, increasing or decreasing its internal volume (expansion and compression). When the internal volume increases, liquid is absorbed from the main channel, lowering the liquid pressure in the main channel, and when the internal volume decreases, liquid is released into the main channel, increasing the liquid pressure in the main channel. By repeatedly lowering and raising the liquid pressure in this manner, the present invention has been achieved in order to create pulsation in the liquid pressure of the main channel. With this configuration, the pulsating flow generator only needs to increase or decrease the internal volume of the volume fluctuation section to fluctuate the liquid pressure, thus avoiding the contradictory configuration of conventional devices that apply pressure to the liquid while simultaneously releasing it, and enabling efficient pulsation of the liquid pressure.

[0010] Moreover, since the main flow path does not require any configuration to pulsate the liquid pressure, it is easy to control the liquid pressure and the flow resistance is low. At this time, there is no need to provide a check valve or the like in the main flow path to straighten the liquid. This is because when the volume fluctuation section releases the absorbed liquid into the main flow path, it superimposes the volume fluctuation pressure on the inlet liquid pressure. In order to release this superimposed pressure, the liquid naturally tries to escape towards the nozzle side with an open end, rather than towards the liquid supply means side where the liquid is supplied by the inlet liquid pressure. Therefore, when the liquid pressure is increased by adding the volume fluctuation pressure to the inlet liquid pressure, the liquid will naturally move towards the open end of the nozzle through the main flow path, even without a check valve or the like. In order to transmit the pulsation of the liquid pressure to the open end of the nozzle without hindering this flow or attenuating it, it is preferable that the main flow path does not have a check valve or the like. Thus, the main flow path is formed within the main body as a single continuous pipe from the intake to the discharge port, simplifying the configuration of the pulsating flow generator and contributing to a reduction in the number of parts required when implementing the pulsating flow generator.

[0011] Thus, according to the first aspect of the present invention, it is not necessary to place a plunger with a through hole in the main flow path through which the liquid flows from the liquid supply means to the nozzle. Therefore, it is not necessary to prepare a plunger with a through hole, nor to install a check valve, which has durability issues, in the through hole of the plunger. As a result, a pulsating flow generator with a simple structure and high durability can be obtained. Furthermore, when the pulsation generation unit reduces (compresses) the internal volume of the volume fluctuation unit, no part of the compressed liquid escapes through the through hole, so the liquid pressure can be increased efficiently.

[0012] Furthermore, according to a second aspect of the present invention, in the first aspect of the present invention, the liquid injection pressure at the open end of the nozzle fluctuates between a first injection pressure obtained by superimposing the volume fluctuation pressure when the volume fluctuation section absorbs the liquid onto the inlet liquid pressure (as a result of the inlet liquid pressure being reduced) and a second injection pressure obtained by superimposing the volume fluctuation pressure when the volume fluctuation section releases the liquid onto the inlet liquid pressure (as a result of the inlet liquid pressure being increased), and the internal volume of the volume fluctuation section is changed so that at least a portion of the liquid injected from the open end of the nozzle forms droplets during flight due to the pressure fluctuation between the first injection pressure and the second injection pressure.

[0013] By configuring the volume fluctuation section in this way, the direct current component of the liquid flow ejected from the nozzle can be minimized, allowing the droplets to act on the target. This makes it possible to maintain or enhance the effect the liquid has on the target while reducing the amount of liquid used.

[0014] Furthermore, according to a third aspect of the present invention, in any one of the above embodiments of the present invention, the cross-section of the main flow channel does not change over time at any position along the flow of the liquid.

[0015] As a result, unless the inlet pressure fluctuates on the liquid supply side, the inlet pressure component of the liquid pressure, excluding the volume fluctuation pressure component, does not fluctuate over time at each position along the liquid flow in the main channel. Therefore, the upper and lower limits of the injection pressure at the open end of the nozzle, where the volume fluctuation pressure is superimposed on the inlet pressure, also do not change over time. Here, the fact that the cross-section of the main channel at a predetermined position along the liquid flow does not change over time also means that there are no on-off valves or the like installed at that position. In conventional pulsating flow generators, the plunger in the channel moves along the channel, so if we focus on a certain position on the movement path of the plunger, the cross-section of the main channel changes over time because, for example, the diameter of the plunger changes due to the movement of the plunger, between the diameter of the plunger and the diameter of the through-hole. The statement that the cross-section of any point along the main flow path does not change over time means that no matter which point in the main flow path you focus on, that cross-section does not change over time, and it also means that no valves, especially check valves or plungers, are installed at any point in the main flow path.

[0016] According to a fourth aspect of the present invention, in any one of the above embodiments of the present invention, the volume fluctuation section begins absorbing liquid at the same time that liquid is supplied from the liquid supply means at the inlet pressure.

[0017] As a result, the volume fluctuation section acts as a temporary liquid storage section (buffer), absorbing the supplied liquid and delaying the time between when the liquid is supplied from the liquid supply means and when it is ejected from the nozzle. This prevents the liquid at the inlet pressure from being ejected in a direct current from the nozzle in the initial stage.

[0018] According to a fifth aspect of the present invention, in any one of the above embodiments of the present invention, the pulsation generating section has a column with an internal bore extending longitudinally inside and communicating with a branch passage, and a plunger fitted into the internal bore of the column and movable in the longitudinal direction of the column, wherein the internal volume of the volume fluctuation section changes as the plunger moves between a discharge position on the branch passage side and a filling position distal to the branch passage than the discharge position, the plunger absorbs the liquid flowing in the main passage as it moves from the discharge position to the filling position, and the liquid is released into the main passage as it moves from the filling position to the discharge position.

[0019] In this configuration, the plunger is used solely to increase or decrease the internal volume of the volume-changing section and thereby change the liquid pressure. Therefore, the plunger does not need to have a through-hole or a corresponding check valve. As a result, when the plunger moves from the discharge position to the filling position, it directly absorbs liquid from the main flow path with little flow resistance, efficiently superimposing the volume-changing pressure on the liquid inlet pressure (in this case, a decrease in pressure). Furthermore, when the plunger moves from the filling position to the discharge position, the liquid does not escape through through-holes or the like, so the volume-changing pressure can be efficiently superimposed on the liquid inlet pressure (in this case, a increase in pressure).

[0020] In yet another aspect of the present invention, in a fifth aspect of the present invention, the plunger is made of a magnetic material, and the plunger is moved by an electromagnetic force acting on the plunger by an electromagnetic field generated by electromagnetic means. In particular, a wound-type solenoid coil is fitted to the outside of the column so as to align the axis of the solenoid coil with the axis of the column, and the plunger is moved by a magnetic field generated by exciting this solenoid coil.

[0021] According to such a configuration, the plunger can be moved by an electromagnetic force that can flexibly set the pattern of the electromagnetic field, compared with a mechanical moving method restricted by a mechanical structure. Therefore, the moving manner of the plunger can be controlled flexibly and easily. In particular, when a solenoid coil is used as an electromagnetic means and the electromagnetic force acting on the plunger is controlled by generating a magnetic field with the current flowing through the solenoid coil, the generation of the magnetic field can be controlled by using a general-purpose current / voltage control technique. Thus, the moving manner of the plunger can be controlled even more flexibly and easily.

[0022] According to still another aspect of the present invention, in the fifth aspect of the present invention, the plunger is configured to be moved by the elastic force of a spring.

[0023] According to such a configuration, the plunger can be moved using the internal energy (elastic energy) stored in the spring without relying on external energy such as electrical energy, which is economical. Also, by appropriately setting variables of the spring such as dimensions and spring constant, a definite movement of the plunger can be uniquely selected.

[0024] According to still another aspect of the present invention, in the fifth aspect of the present invention, the plunger is made of a magnetic material, and is configured to be moved from the release position to the filling position by electromagnetic means and then moved from the filling position to the release position by the elastic force of the spring.

[0025] According to such a configuration, it is possible to absorb the liquid into the internal volume while suppressing the drop in the liquid injection pressure by moving the plunger from the discharge position to the filling position while electromagnetically controlling the speed, as if pulling a bow and releasing an arrow. On the other hand, by quickly moving the plunger from the filling position to the discharge position using the elastic force of the spring, the liquid can be discharged at once and the pressure of the liquid can be effectively increased. At this time, the plunger is moved from the discharge position to the filling position while resisting the elastic force of the spring by allocating a relatively long time within, for example, the time required for one stroke (for example, 10 ms). Therefore, there is no risk that the plunger will collide with some member on the filling position side due to excessive momentum. Also, when moving the plunger from the filling position to the discharge position, there is no need to arrange a member of electromagnetic means (for example, a magnetic head described later) that attracts the plunger to a position facing the plunger. Therefore, there is no risk that the plunger will collide with the opposing member (for example, the magnetic head described later) due to excessive momentum, and noise caused by the collision of the plunger can be avoided in any scenario. Further, since the variables of the spring (dimensions, spring constant, etc.) that characterize the spring are invariant, a stable volume fluctuation pressure, and thus a second injection pressure, can be obtained when the liquid is discharged. And when the liquid is supplied from the liquid supply means at the liquid injection pressure and at the same time the plunger is moved from the discharge position to the filling position, it can be controlled so that an electromagnetic force acts on the plunger in accordance with the supply of the liquid from the liquid supply means. Therefore, the volume fluctuation part is used as a temporary storage part (buffer) of the liquid to absorb the supplied liquid, and the time from when the liquid is supplied from the liquid supply means until the liquid is ejected from the nozzle is delayed. As a result, the liquid at the liquid injection pressure is not ejected directly from the nozzle at the initial stage.

[0026] According to still another aspect of the present invention, in the fifth aspect of the present invention, the plunger is made of a magnetic material, and the plunger is moved from the discharge position to the filling position by the elastic force of the spring, and is configured to be moved from the filling position to the discharge position by electromagnetic means.

[0027] With this configuration, the speed at which the plunger moves from the filling position to the discharge position can be freely adjusted by electromagnetic force, allowing for free adjustment of the volume fluctuation pressure and, consequently, the second injection pressure. This makes it easier to adjust droplet formation, while when the electromagnetic force is removed, the plunger automatically returns to the filling position due to the elastic force of the spring. Moreover, since the spring variables (dimensions, spring constant, etc.) that characterize the spring remain unchanged at this time, a stable first injection pressure can be obtained.

[0028] According to yet another aspect of the present invention, in any of the above yet another aspect of the present invention, a biasing spring is arranged on one side of the plunger, and a retaining spring is arranged on the opposite side of the plunger from the biasing spring.

[0029] With this configuration, when the plunger is moved by the elastic force of the spring, the plunger, which has gained momentum from being pushed by the biasing spring, is supported by the holding spring, thus preventing the plunger from colliding with anything. Furthermore, in the standby state when no liquid is being supplied, the balance of the elastic forces between the biasing spring and the holding spring allows the plunger to be stably held (suspended) in a predetermined position.

[0030] According to yet another aspect of the present invention, in any of the above yet another aspect of the present invention, a wound-type solenoid coil is fitted onto the outside of a column such that the axis of the solenoid coil aligns with the axis of the column, and magnetic path forming tubes are fitted between the outer surface of the column and the inner surface of the solenoid coil from both ends of the column, and these magnetic path forming tubes are arranged at an intermediate position in the longitudinal direction of the column such that they form a gap between them (magnetic leakage type electromagnetic means).

[0031] In this configuration, when an electric current is passed through the solenoid coil to generate a magnetic field, that field passes through the magnetic path forming tube, and a plunger made of magnetic material moves as if being attracted to the gap in the magnetic path to lower the magnetic resistance in the gap. At the same time, since there is nothing inside the tube column to obstruct the movement of the plunger, the plunger can move freely inside the tube column.

[0032] According to yet another aspect of the present invention, in any of the above yet another aspect of the present invention, a wound-type solenoid coil is fitted to the outside of a column such that the axis of the solenoid coil aligns with the axis of the column, and a magnetic head made of a magnetic material is positioned at one end of the column so as to face one end face of a plunger (internal magnetic circuit type electromagnetic means).

[0033] With this configuration, the plunger can move by being attracted to the magnetic head, which is magnetized by exciting the solenoid coil, resulting in an overall compact design.

[0034] Although various embodiments of the present invention have been described above, the present invention is not limited to any of the above embodiments and can be freely combined to form other embodiments as appropriate. The present invention can be described in any of the above embodiments, or in any of the other embodiments formed by various combinations of the above embodiments, as disclosed herein.

[0035] The pulsating flow generator according to the present invention will be described in detail below based on embodiments with reference to the drawings. [Brief explanation of the drawing]

[0036] [Figure 1] This is a cross-sectional view of a pulsating flow generating device according to the present invention. [Figure 2] This is a perspective view of the pulsating flow generator according to the present invention. [Figure 3] This is an exploded perspective view of the pulsating flow generator according to the present invention. [Figure 4] This diagram illustrates the principle of the pulsating flow generator according to the present invention. [Figure 5] This diagram illustrates the principle of a conventional pulsating flow generator. [Modes for carrying out the invention]

[0037] (Cleaning device) The pulsating flow generator 1 of the present invention, shown in Figures 1 to 3, is used in a washing device such as a heated toilet seat and is installed in the flow path between a supply mechanism (liquid supply means) (not shown) that supplies water (liquid) at the inlet pressure (inlet liquid pressure) and a nozzle (not shown) of the washing device that sprays the supplied water from its open end. The water supply mechanism upstream of the pulsating flow generator 1 is configured to supply water supplied through a water supply pipe to an on / off valve that can be opened and closed after appropriately increasing or decreasing the pressure using a booster pump or pressure reducing valve, and to control the start and stop of water supply by opening and closing the on / off valve. With this configuration of the water supply mechanism, when the on / off valve is closed, water is not supplied to the pulsating flow generator 1 and the nozzle side, and the downstream side of the on / off valve is filled with water at a residual pressure such that water does not flow out of the nozzle (the water may be drained if necessary). When the on / off valve is opened, water is supplied towards the nozzle side at the inlet pressure (inlet liquid pressure). The pulsating flow generator 1 is configured to pulsate the pressure of the water flowing through the channel (liquid pressure), thereby changing the amount of water (liquid flow rate) ejected from the nozzle in accordance with the pressure pulsation. The water ejected from the nozzle deforms during flight, particularly forming water droplets (liquid droplets), which allows for the maintenance or enhancement of cleaning power on the object being cleaned while reducing the amount of water used in cleaning devices such as heated toilet seats.

[0038] (Pulsating flow generator) As shown in Figures 1 to 3, the pulsating flow generator 1 used in this way has a main body 2 in which a main flow path is formed inside through which water flows from a water supply mechanism toward a nozzle, and a pulsating generation unit 4 equipped with a volume fluctuation unit that alternately absorbs and releases water flowing through the main flow path by increasing or decreasing its internal volume, via a branch path into which a flow path branches off from the main flow path. The pulsating generation unit 4 is connected to the main body 2, and the connection between the pulsating generation unit 4 and the main body 2 is maintained by a stay 6 that clamps them together. The main flow path of the pulsating flow generator 1 is connected such that an intake port 23 opening at one end communicates with the flow path on the water supply mechanism side, and an outlet port 24 opening at the other end communicates with the flow path on the nozzle side.

[0039] (Main channel of main body) The main body 2 of the pulsating flow generator 1 has an intake-side connector 21 on the water supply mechanism side and a discharge-side connector 22 on the nozzle side. An intake port 23 opened at the end of the intake-side connector 21 is connected to the flow path on the water supply mechanism side, and an outlet port 24 opened at the end of the discharge-side connector 22 is connected to the flow path on the nozzle side. A communication hole 26 is formed in the portion of the main body 2 between the intake-side connector 21 and the discharge-side connector 22 to connect the intake port 23 and the discharge port 24, and the entire flow path from the intake port 23 to the discharge port 24 is formed as the main flow path of the main body 2. No check valves or other valves are provided in this main flow path, and the main flow path is configured such that, although there may be some deformation due to heat and water pressure, it does not undergo elastic deformation and the cross-section at any position along the water flow does not change over time.

[0040] (Main unit, branching section, connection section) Furthermore, the main body 2 has a branch section 28 in which a branch channel is formed inside from the main flow channel. The space forming the branch channel does not change its internal volume and therefore becomes part of the water storage section (liquid storage section). A connection section 30 for connecting to the pulsation generation section 4 is formed at the end of this branch section 28.

[0041] (Pulsation generation section, volume fluctuation section) The pulsation generating unit 4, which is connected to the main body 2 via the connection part 30 of the main body 2, has a substantially cylindrical tube column 41 that extends longitudinally and whose interior is in communication with the branching path, and a substantially cylindrical plunger 42 made of magnetic material that has an outer diameter approximately the same as the inner diameter of the tube column 41 and is fitted into the tube column 41 in a liquid-tight manner. The plunger 42 is provided so as to be able to reciprocate inside the tube column 41 in its longitudinal direction between the discharge position on the branching path side and the filling position distal to the branching path, and the tube column 41 and the plunger 42 cooperate to define the internal volume on the branching path side, and constitute a volume fluctuation unit in which the internal volume changes as the plunger 42 moves. The pulsation generation unit 4 is configured to alternately repeat a filling process in which the plunger 42 moves from the discharge position to the filling position within the pipe column 41, increasing the internal volume of the volume fluctuation section and absorbing liquid from the main flow path, and a discharge process in which the plunger 42 moves from the filling position to the discharge position within the pipe column 41, decreasing the internal volume of the volume fluctuation section and releasing liquid into the main flow path. The fluctuating plunger pressure (volume fluctuation pressure) is superimposed on the water inlet pressure to cause the liquid pressure to pulsate. Here, when the plunger 42 is in the discharge position, the internal space of the pipe column 41 on the branching channel side of the plunger 42 does not change in internal volume and forms a water storage section (liquid storage section) together with the space that forms the branching channels of the branching section 28 and the connecting section 30.

[0042] (Pulsation generation section: plunger drive mechanism) A bobbin 44 is fitted onto the outside of the column 41 so that its axis aligns with the axis of the column 41. A coil 45 with a winding is attached to the outer circumference of the bobbin 44, and the bobbin 44 and coil 45 form an integrated solenoid coil. A C-shaped yoke 46 is attached to connect both sides of the solenoid coil in the longitudinal direction. The coil 45 is provided with terminals (not shown) and is electrically connected to a power supply (not shown) that can be controlled by a control unit (not shown).

[0043] Between the outer surface of the column 41 and the inner surface of the bobbin 44, a magnetic path forming tube 47 on the filling position side and a magnetic path forming tube 48 on the discharge position side are fitted from the upper and lower ends of the column 41 in Figure 1, respectively, and are arranged to form a gap G between the magnetic path forming tubes 47 and 48 at an intermediate position in the longitudinal direction of the column 41. A magnetic head 49 made of magnetic material is fitted from the side of the column 41 distal to the branching path (upper end side in Figure 1) so as to face the end face of the plunger 42 distal to the branching path (upper end face in Figure 1). The magnetic head 49 has a projection 491 that extends toward the plunger 42 in order to exert the strongest possible magnetic force on the plunger 42, but its length is appropriately adjusted so that it does not collide with the projection 491 and generate noise even when the plunger 42 rises to the filling position. These magnetic path forming tubes 47 on the filling side, 48 on the discharge side, and magnetic head 49 are connected to each other by a yoke 46, and together with a plunger 42 made of magnetic material, they form a single magnetic path including a gap G. When a coil magnetic field is generated by supplying current to the coil 45 from a power supply controlled by a control unit, the plunger 42 is moved (by electromagnetic means) so that the magnetic field reduces the magnetic resistance of the magnetic path passing through it.

[0044] Furthermore, a biasing spring 50 (spring) is interposed between the end face of the plunger 42 distal to the branching path (upper end face in Figure 1) and the end face of the magnetic head 49 on the plunger 42 side, and a retaining spring 51 is interposed between the end face of the plunger 42 on the opposite side of the biasing spring 50 (lower end face in Figure 1) and the branching portion 28 (upper surface) of the main body 2. In a standby state where no current is supplied to the coil 45, the balance of the elastic forces between the biasing spring 50 and the retaining spring 51 positions the plunger 42 in a suspended state at a predetermined intermediate position in the longitudinal direction of the tube column 41. At the same time, when the plunger 42 moves from the filling position to the discharge position, the retaining spring 51 dampens the movement of the plunger 42, and ultimately brings the plunger 42 to rest at the discharge position without colliding with anything.

[0045] (Connection structure between the main unit and the pulsation generating unit) The connection portion 30 of the main body 2 for connecting the main body 2 to the pulsation generating section 4 is formed on the terminal side of the branch section 28 distal to the main flow path. This connection portion 30 consists of an annular pipe column support portion 31 connected to the terminal side of the branch section 28 and supporting the end face (lower end in Figure 1) of the pipe column 41 on the branch path side, a sealing portion 32 protruding from the outer edge of the pipe column support portion 31 and housing an O-ring 52a between itself and the outer surface of the pipe column 41, and an annular flange 33 provided on the terminal side of the sealing portion 32 and connected to the yoke 46 of the pulsation generating section 4 and the end face of the magnetic path forming pipe 48.

[0046] Furthermore, to prevent the main body 2 and the pulsation generating unit 4, which are connected to each other, from separating again, a stay 6 is attached so as to sandwich the side of the flange 33 of the connecting unit 30 that faces the branch road and the side of the yoke 46 that faces the branch road. This stay 6 is configured to hold the main body 2 and the pulsation generating unit 4 in place, thereby maintaining the connection between them.

[0047] (Sealed structure) Furthermore, the inside of the pulsating flow generator 1 through which water flows and the outside which is open to the outside air are sealed liquid-tight by an O-ring 52a housed in the space between the outer surface of the tube column 41 and the inner surface of the sealing part 32, and pressed against these surfaces. In addition, an O-ring 52b housed in a recess on the outer circumference of the magnetic head 49 and pressed against the inner surface of the tube column 41 prevents water that may enter the upper side of the plunger 42 from between the inner surface of the tube column 41 and the outer surface of the plunger 42 from escaping to the outside.

[0048] (filling process) As described above, the pulsating flow generator 1 is in a standby state while the on / off valve of the upstream water supply mechanism is closed, and the plunger 42 is positioned and held in a position where the elastic forces of the biasing spring 50 and the retaining spring 51 are balanced. When the on / off valve is opened, water is supplied from the supply mechanism side at an inlet pressure of, for example, about 0.051 MPa, and at the same time, the power supply is controlled by the control unit and current is supplied to the coil 45 (in a predetermined pattern if necessary), and the coil 45 is energized. The plunger 42 is first pulled into the gap G between the magnetic path forming tubes 47 and 48 (the plunger 42 fills the gap G (effectively shortening the gap)) so that the magnetic field generated by the coil 45 reduces the magnetic resistance of the magnetic path passing through it, and then it is pulled more and more strongly towards the magnetic head 49, reducing the distance between it and the magnetic head 49, and is pulled up against (mainly) the elastic force of the biasing spring 50 (and the tensile force of the retaining spring 51) to the upper filling position in Figure 1. At this time, the internal space of the volume fluctuation section defined by the plunger 42 and the tube column 41 expands and widens, increasing its internal volume. The water supplied by the inlet water pressure flowing through the main channel is absorbed into the volume fluctuation section with increasing internal volume via a branch channel branching off from the main channel (filling process). When the plunger 42 reaches the filling position, the elastic energy of the biasing spring 50 reaches its maximum. At this time, the current supplied to the plunger 42 is controlled so that the pressure drop due to the plunger pressure (volume fluctuation pressure) does not become too large due to the rapid absorption of water, and a predetermined first injection pressure of liquid of, for example, about 0.005 to 0.05 MPa, preferably about 0.009 MPa, is obtained at the open end of the nozzle. Furthermore, when the plunger 42 is moved to the filling position at that speed, a small gap remains between the upper surface of the plunger 42 and the lower surface of the protrusion 491 of the magnetic head 49. This is adjusted so that the magnetic force of the magnetic head 49 acts on the plunger 42 as strongly as possible, while preventing the plunger 42 from colliding with the magnetic head 42 and generating noise.

[0049] (Release process) Once the filling process of the pulsating flow generator 1 is complete, the power supply is controlled by the control unit, and the supply of current to the coil 45 is stopped (in a predetermined pattern if necessary), and the magnetic field generated by the coil 45 disappears. Then, the elastic force of the biasing spring 50 and the tensile force of the retaining spring 51 bias the plunger 42 toward the branch road side (the lower side in Figure 1), and the plunger 42 moves from the filling position toward the branch road side. Finally, the plunger 42 stops at the release position where the retaining spring 51 is compressed to a certain extent. At this time, the branch road side surface of the plunger 42 is supported by the retaining spring 51, preventing collision with the branch road side and avoiding the generation of noise. Thus, as the plunger 42 moves from the filling position to the discharge position, the water absorbed in the internal volume of the volume fluctuation section is discharged into the main flow path by reducing the internal volume. As shown in Figure 4, the plunger pressure (volume fluctuation pressure) is superimposed on the inlet water pressure, and at the open end of the nozzle, the water pressure is increased to a second injection pressure of, for example, 0.10 MPa to 0.18 MPa, preferably 0.108 MPa (discharge process). The spring variables such as the dimensions and spring constant of the biasing spring 50 are appropriately selected, along with the spring variables of the retaining spring 51, so that a desired second injection pressure can be obtained.

[0050] (Operating status) As soon as the above discharge process is completed, the next filling process is started, and the pulsating flow generator 1 alternately repeats (up and down movement in Figure 4) a filling process in which the internal volume of the volume fluctuation section is increased to absorb water from the main flow path, and a discharge process in which the internal volume of the volume fluctuation section is decreased to release water into the main flow path, thereby superimposing the fluctuating plunger pressure on the water inlet pressure and causing the water pressure to pulsate.

[0051] As a result of the plunger pressure being superimposed on the inlet water pressure, the water injection pressure at the nozzle's open end fluctuates between a first injection pressure when the volume-fluxing section absorbs liquid and a second injection pressure when the volume-fluxing section releases liquid. At this time, the amount of movement (stroke) of the plunger 42 between the filling position and the release position, the corresponding amount of change in the internal volume of the volume-fluxing section (depending on the dimensions of the plunger 42, etc.), spring variables such as the spring constants of the biasing spring 50 and the retaining spring 51, and the waveform of the voltage applied to the coil 45 when supplying current to the coil 45 are set such that the internal volume of the volume-fluxing section changes so that the water injected from the nozzle's open end is interrupted during flight by the pressure fluctuation between the first and second injection pressures, forming water droplets (not becoming a direct current) (for example, a pressure difference of about 0.099 MPa is obtained for a first injection pressure of about 0.009 MPa and a second injection pressure of about 0.108 MPa).

[0052] (effect) As described above, the pulsating flow generator 1 of the present invention does not have a through hole in the plunger 42, so water can be absorbed using the entire end face of the plunger 42. Moreover, the flow area of ​​the branch channel can be made wider, and there is no water resistance on the opposite side of the plunger 42 from the branch channel. As a result, in the filling process of the pulsating flow generator 1, which absorbs water from the main channel through the branch channel, the plunger does not move while receiving resistance from the water as in the conventional method, and water is not filled through a small through hole in the plunger, so water can be absorbed efficiently with less resistance. Also, in the discharge process of the pulsating flow generator 1, water does not escape through a through hole in the plunger as in the conventional method, so water can be discharged without waste. Thus, the pulsating flow generator 1 of the present invention makes it possible to efficiently superimpose the plunger pressure on the water flowing in the main channel with the inlet water pressure, thereby causing the water pressure to pulsate.

[0053] Furthermore, the plunger 42 does not require the machining of a through hole, making it easy to manufacture. In addition, it does not require the use of components with durability issues, such as check valves that have been conventionally installed in through holes, resulting in high durability and significantly extending the service life and maintenance period of the pulsating flow generator 1.

[0054] Furthermore, the main flow path provided in the main body 2 of the pulsating flow generator 1 according to the present invention is integrally formed inside the main body 2 from the water intake port 23 to the discharge port 24, thus reducing the number of parts. Moreover, even without providing a flow straightening valve or the like inside the main flow path, water is naturally allowed to flow to the open end of the nozzle due to the water pressure from the water supply mechanism, thereby reducing the internal flow resistance. Furthermore, since there is no change in the water flow rate due to the opening and closing of valves in the main flow path, the upper and lower limits of the injection pressure at the open end of the nozzle, where the plunger pressure is superimposed on the inlet water pressure, do not change over time, enabling stable water injection.

[0055] Furthermore, the first injection pressure of the liquid at the open end of the nozzle when the volume fluctuation section of the pulsating flow generator 1 according to the present invention absorbs water can be freely set by adjusting the speed of the plunger 42 by controlling the current supplied to the coil 45, and at this time, the plunger 42 can be prevented from colliding with the magnetic head 49 and generating noise. On the other hand, the second injection pressure when the volume fluctuation section of the pulsating flow generator 1 discharges water can be stably set by appropriately selecting spring variables such as the spring constants of the biasing spring 50 and the retaining spring 51. In this way, the internal volume of the volume fluctuation section of the pulsating flow generator 1 can be changed to form water droplets during flight by pressure fluctuations between the first injection pressure and the second injection pressure, so that the water droplets clean the object to be cleaned while minimizing the DC component of the water flow ejected from the nozzle, and the cleaning power on the object to be cleaned can be maintained or increased while suppressing the amount of water used.

[0056] (Other embodiments) Although one embodiment of the pulsating flow generator 1 according to the present invention has been described above, it goes without saying that the present invention is not limited to this embodiment and can be implemented in various ways.

[0057] For example, in the above embodiment, the plunger is moved to the filling position by electromagnetic force and returned to the discharge position by the elastic force of a spring. However, it is also acceptable to move it to the filling position by the elastic force of a spring and return it to the discharge position by electromagnetic force. This allows for flexible adjustment of the second injection pressure when the volume fluctuation section discharges the liquid, for example, by controlling the current flowing through the coil. Furthermore, if necessary, both moving the plunger to the filling position and moving it to the discharge position can be done using electromagnetic force.

[0058] Alternatively, in the above embodiment, both a magnetic path forming tube and a magnetic head are used as members that form the magnetic path. However, by using only a magnetic path forming tube, it is possible to avoid placing any members that might collide with the tube column in which the plunger moves. Conversely, by using only a magnetic head, the size of the device can be reduced.

[0059] Furthermore, various configurations are possible for branching off from the main channel. One possibility is to arrange multiple branch channels around the axis on the inner surface of the pipe forming the main channel, or to form branch channels that encircle it (in this case, the main channel is divided into an upstream side and a downstream side), and to absorb liquid from the main channel through these branch channels and release it back into the main channel.

[0060] Similarly, the shape of the volume-changing section can be anything other than a cylinder, and it can certainly be an irregular shape using a membrane or the like.

[0061] Furthermore, the orientation of the volume-changing section may be aligned with that of the main flow path (in this case, the branch path that branches off perpendicularly from the main flow path will bend 90° towards the main flow path midway), or the position of the volume-changing section relative to the main flow path may be changed. Not only may the volume-changing section be located outside the main flow path, but to save installation space, the main flow path may also be passed through the volume-changing section. In this case, the main flow path passes through the center of the pipe column, and the donut-shaped volume-changing section is arranged from there via branch paths. The plunger is formed in a ring shape so as to be fitted into the donut-shaped space between the main flow path and the pipe column.

[0062] Regardless of the above embodiment of the pulsating flow generator, it has a simple structure, high durability, and can efficiently pulsate the pressure of the liquid flowing through the channel. [Explanation of Symbols]

[0063] 1. Pulsating flow generator 2 Main unit 21 Intake side connector 22 Discharge side connector 23 Inlet 24 Outlet 26 Communication hole 28 Branching point 30 Connection part 31 Pipe support part 32 Sealing part 32 flange 4. Pulsation generation section 41 Tube pillar 42 plungers 44 bobbins 45 coils 46 York 47 Magnetic path forming tube on the filling position side 48 Magnetic path forming tube on the discharge side 49 Magnetic Head 491 Protrusion 50 biasing spring 51 Retaining spring 52a O-ring on the main body side 52b O-ring on the magnetic head side 6 Stay 100 Inlet 200 flow paths 300 outlet 400 plungers 500 through holes 600 Check valve

Claims

1. A pulsating flow generator is provided in a flow path between a liquid supply means that supplies liquid at an inlet pressure and a nozzle that sprays the supplied liquid from an open end, and by pulsating the pressure of the liquid flowing through the flow path, it causes a change in the flow rate of the liquid sprayed from the nozzle in accordance with the pressure pulsation, A main body having a main channel through which liquid flows from the liquid supply means toward the nozzle, The system includes a pulsation generating unit equipped with a volume fluctuation section that alternately absorbs and releases the liquid flowing through the main channel by increasing or decreasing its internal volume, via a branch path from which a flow path branches off from the main channel. The pulsation generation unit is characterized in that, when the liquid supply means is supplying liquid at the input liquid pressure, it alternately repeats a filling step of increasing the internal volume of the volume fluctuation unit to absorb liquid from the main flow path and a discharge step of decreasing the internal volume of the volume fluctuation unit to release liquid into the main flow path, thereby superimposing the fluctuating volume fluctuation pressure on the pre-filled liquid pressure of the liquid and causing the liquid pressure to pulsate.

2. The pulsating flow generator according to claim 1, characterized in that the liquid injection pressure at the open end of the nozzle fluctuates between a first injection pressure obtained by superimposing the volume fluctuation pressure when the volume fluctuation section absorbs the liquid on the input liquid pressure and a second injection pressure obtained by superimposing the volume fluctuation pressure when the volume fluctuation section releases the liquid on the input liquid pressure, and the internal volume of the volume fluctuation section is changed such that at least a portion of the liquid injected from the open end of the nozzle forms droplets during flight due to the pressure fluctuation between the first injection pressure and the second injection pressure.

3. The pulsating flow generator according to claim 1, characterized in that the cross-section of the main flow channel does not change over time at any position along the flow of the liquid.

4. The pulsating flow generating device according to claim 1, characterized in that the volume fluctuation section starts absorbing liquid at the same time that liquid is supplied from the liquid supply means at the inlet pressure.

5. The pulsation generating unit comprises a column with an internal bore extending longitudinally and communicating with the branch passage, and a plunger fitted into the internal bore of the column and movable longitudinally, wherein the internal volume of the volume variation unit changes as the plunger moves between a discharge position on the branch passage side and a filling position distal to the branch passage than the discharge position, the plunger absorbs the liquid flowing in the main passage as it moves from the discharge position to the filling position, and the plunger releases the liquid into the main passage as it moves from the filling position to the discharge position, as described in any one of claims 1 to 4.

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