JPH0520598B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pump that moves a cover using an actuator and changes the cross section of the water flow path by the cover to freely change the amount of water delivered. In particular, the present invention relates to a pump that prevents cavitation and improves the durability of the cover and vanes.

[Description of Prior Art] In conventional pumps for water-cooled engines, the maximum water flow of the pump is adjusted to the full-load operating range in which the engine releases the maximum amount of heat, so in the partial-load operating range, more water than necessary is circulated. The drawback was that energy was wasted.

In order to improve this conventional drawback, the present applicant proposed a system in which the amount of output from the pump could be freely adjusted by moving the cover constituting the wall surface of the distribution channel using an actuator. - Proposed by No. 99033. FIG. 4 shows a diagram of the relationship between the blade and the cover in this configuration example, and FIG. 5 shows a side view in the direction of arrow A in FIG. 4.

In the casing 10, a suction passage 12, which is a fluid passage, and a discharge passage 14 communicating with the suction passage 12 are formed. A rotary shaft 16 is rotatably held within the casing 10, and an impeller 20 having a plurality of blades 18 integrally formed therein is fixed to the rotary shaft 16.

A cover 22 for adjusting the effective length of the blade 18 is fixed to the tip of a sliding rod 24 of an actuator (not shown), and the cover 22 is slidable in the direction of extension of the blade 18 by the actuator. . This cover 22 has a circular end surface 26
and a cylindrical skirt portion 28 that slides into contact with the outer edge of the impeller 20 on the outer edge of the circular end surface 26, and a plurality of holes for passing the blades 18 through the circular end surface 26. 30 is formed. Each of the blades 18 is inserted through each hole 30, and each blade 18 is prevented from coming off from the hole 30 during the stroke of the cover 22. A joint 32 is attached to the other end of the sliding rod 24 for sliding the cover 22 while allowing the cover 22 to rotate.

In this way, the cover 2 is controlled by the actuator.
By sliding 2, the effective length of the blade can be adjusted, and the amount of water to be fed can be adjusted in accordance with the operating conditions of the engine.

[Problems to be Solved by the Invention] In the conventional configuration, the blade 18 is covered with a cover 22.
The hole 30 projects into the water flow path. Therefore, when discharging the maximum flow rate, the protrusion width of the blade 18 becomes the maximum and the rotation speed also becomes the maximum.
There was a problem in that cavitation occurred in the distribution channel due to the influence of the rotation of the tip of the blade 18.

Furthermore, since the cover 22 is rotated by the blades 18 and the cover 22 slides against the blades 18, there is a problem that wear occurs at the contact points between them.

Moreover, since the sliding rod 24 and the cover 22 are rotated together with the vane 18, it is necessary to provide a joint 32 for sliding the cover 22 while allowing the rotation of the cover 22.

[Object of the Invention] The present invention has been made in view of the above points, and it is possible to cover the tip of the blade with a cover to prevent the tip of the blade from being exposed to the flow path of water, and furthermore, the cover is designed to co-rotate with the blade. The purpose of this invention is to provide an economical pump which prevents cavitation from occurring and also improves the durability of the cover and vanes.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a casing having a fluid passage formed therein, a plurality of vanes attached to a rotating shaft for moving fluid,
In the pump, the cover is provided with a cover that is slid in the axial direction of the rotating shaft to vary the cross section of the fluid passage, and an actuator that adjusts the amount of movement of the cover, and the cover is a cylinder, and the cylinder wall is arranged inside the pump. A double wall consisting of a cylindrical wall and an external cylindrical wall, a cylindrical space with one end closed in which the blade can freely rotate is formed between the internal cylindrical wall and the external cylindrical wall, and the inner cylindrical wall of the cover The inner side of the fluid passage is an intermediate route of the fluid passage, the tips of the vanes are housed in the cylindrical space throughout the entire stroke of the cover, and the passage cross section of the fluid passage is varied on the wall surface of the cylindrical body of the cover. It is.

[Operation] A blade is rotatably inserted in the cylindrical space between the inner cylindrical wall and the outer cylindrical wall of the cover. This prevents the cover from rotating independently of the rotation of the blades.

Further, one end side of the cylindrical space is closed, and the tips of the blades are always located within the space during the entire stroke of the cover. This cylindrical space is different from the flow path. As a result, the tips of the blades are housed within the cover and are not exposed to the circulation path.

An internal passage forming a part of the fluid passage is formed inside the internal cylindrical wall of the cover, and the internal passage and the discharge passage are opened and closed by the external cylindrical wall on the open side of the cover.

[Example] Next, the present invention will be explained based on the drawings.

FIG. 1 is a sectional view of a main part of an embodiment of a pump according to the present invention, showing a state in which the fluid passage is slightly opened. FIG. 2 is a configuration diagram showing the positional relationship between the cover and the blade when the fluid passage is closed;
FIG. 3 shows a front view of the cover in the direction of arrow B in FIG. In FIGS. 1 and 2, the same reference numerals as in FIG. 4 indicate the same parts.

Inside the casing 40, a suction passage 42 that reaches the position of the blade 18 and a discharge passage 44 that communicates with the suction passage 42 are formed. The discharge passage 44 is arranged perpendicularly to the direction in which the blades 18 extend.

The cover 46 has a cylindrical shape consisting of double wall surfaces of an inner cylindrical wall 48 and an outer cylindrical wall 50, and a cylindrical space 52 is formed between the inner cylindrical wall 48 and the outer cylindrical wall 50. The blade 18 is inserted into this cylindrical space 52, and the dimensions and shape of this cylindrical space 52 are as follows:
The blades 18 are set so that they can freely rotate without interfering with the inner cylinder wall 48 or the outer cylinder wall 50. That is, even if the blade 18 rotates, the cover 46 is prevented from rotating. Further, the tip of the blade 18 is always inserted into the space 52 during the stroke of the cover 22. The side of the cylindrical space 52 on which the blade 18 is inserted is open, but the opposite side thereof is a closed end surface 54.

The space inside the internal cylindrical wall 48 is an internal passage 56 that becomes a part of the fluid passage. Its internal passage 5
One side of 6 is covered with an end surface 58 continuous from the closed end surface 54. A plurality of holes 60 are formed in this end surface 58, and the suction passage 42 and the internal passage 56 are communicated through the holes 60. The internal passage 56 and the discharge passage 44 are communicated or closed by an external cylindrical wall 50 on the open end side of the cover 46.

An actuator 62 for sliding the cover 46 in the longitudinal direction of the blade 18 is attached to the casing 40. This actuator 6
2 is a diaphragm 64 and the diaphragm 6
Atmospheric chamber 66 and negative pressure chamber 6 divided by 4
8, a spring 70 provided in the negative pressure chamber 68 and pressing the diaphragm 64 toward the atmospheric chamber 66;
It consists of a diaphragm 64 at one end and a sliding rod 72 fixed at the other end to the end surface 58. The negative pressure chamber 68 communicates with an intake manifold (not shown) via a negative pressure passage 76 having a solenoid valve 74 in the middle. The solenoid valve 74 is opened and closed according to operating conditions by an electronic control circuit (not shown). The sliding rod 72 is connected to the negative pressure chamber 68.
It penetrates the partition wall 78 of the casing 40, passes through the suction passage 42, and reaches the cover 46. This partition wall 78 includes a suction passage 42 and a negative pressure chamber 68.
A shield member 80 is attached to seal the space between the two.

In the present invention configured as described above, the blades 18 rotate without interfering with the cover 46. That is, the cover 46 is only slid by the actuator 62 and is not rotated.

Next, when the cover 46 is pushed to the maximum toward the impeller 20 as shown in FIG. It is closed by a cylindrical wall 50. Thereafter, as the cover 46 is pulled toward the actuator 62, the cross section of the communication portion is gradually opened (FIG. 1). At this time, water from the pump passes through the hole 60 in the end face 58 of the cover 46 from the suction passage 42 to the internal passage 56, and flows from the internal passage 56 to the discharge passage 44. Therefore, the actuator 62
By moving the cover 46, the amount of water flowing out can be adjusted.

During the entire stroke of the cover 46, the tips of the vanes 18 are always inserted into the cylindrical space 52. Since the cylindrical space 52 is separate from the water flow path, there is no effect of cavitation on the water flow path due to the tips of the blades 18.

The negative pressure chamber 68 of the actuator 62 is placed adjacent to the partition wall 78. This allows the cover 46 to be removed from the actuator 62 in the event of a failure of the actuator 62.
By moving it to the side, the discharge passage 44 is fully opened to ensure safety.

In the embodiment, the actuator 62 is operated under negative pressure, but a motor or a solenoid may be used, or it may be linked with an accelerator.

[Effects of the Invention] As described above, according to the pump according to the present invention, the cover has a double cylindrical wall including an inner cylindrical wall and an outer cylindrical wall, and a cylindrical space with one end closed is formed between the walls,
The blades are rotatably inserted into the cylindrical space, and a water flow path is formed inside the inner cylindrical wall of the cover. Therefore, since the tips of the blades are not exposed to the water flow path, cavitation can be prevented from occurring.

Furthermore, since the cover does not need to be rotated together with the blade, there is no need for a conventionally used joint, and costs can be reduced.

Furthermore, since the cover does not need to rotate together with the blades, the cover no longer slides while contacting the blades, which eliminates the occurrence of wear at the contact points between the cover and the blades, which previously occurred. It disappears.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the main parts of an embodiment of the pump according to the present invention, FIG. 2 is a configuration diagram showing the positional relationship between the cover and the blade when the water flow is at a minimum, and FIG.
The figure is a front view of the cover in the direction of arrow B in figure 2.
The figure is a configuration diagram showing the relationship between the blade and the cover in a conventional example, and FIG. 5 is a side view shown by arrow A in FIG. 4. 16...Rotating shaft, 18...Blade, 40...Casing, 42...Suction passage, 44...Discharge passage,
46...Cover, 48...Inner cylindrical wall, 50...Outer cylindrical wall, 52...Cylindrical space, 54...Closed end surface, 56...Inner passage, 62...Actuator.

Claims (1)

[Claims] 1. A casing with a fluid passage formed inside;
A plurality of vanes attached to a rotating shaft for moving fluid, a cover that is slid in the axial direction of the rotating shaft to vary the cross section of the fluid passage, and an actuator that adjusts the amount of movement of the cover. In the pump, the cover is a cylinder, the cylinder wall is a double wall consisting of an inner cylinder wall and an external cylinder wall, and one end between which the blade can freely rotate is provided. A closed cylindrical space is formed, the inside of the inner cylindrical wall of the cover is used as an intermediate path of the fluid passage, the tips of the blades are accommodated in the cylindrical space during the entire stroke of the cover, and the cylindrical body of the cover is closed. A pump characterized in that a passage cross section of the fluid passage is varied on a wall surface of the pump.