JPH0152598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pump impeller made of synthetic resin.

[Conventional technology]

As this type of pump impeller, JP-A-56-
As shown in No. 72293, a structure developed by the applicant is known. That is, a front shroud made of synthetic resin is provided with a vane portion having a hollow portion, a recessed groove is provided in a rear shroud made of synthetic resin opposite to this vane portion, and an inner bottom of the recessed groove is provided on the end face of the vane portion. A pump impeller is known in which a projection is continuously or intermittently provided to be ultrasonically welded to the pump impeller.

[Problem to be solved by the invention]

In the above-mentioned conventional pump impeller, if the protrusions are continuously provided on the end face of the vane, the air accumulated in the hollow part of the vane will be compressed when the end face of the vane is ultrasonically welded to the inner bottom of the groove. This makes ultrasonic welding difficult, and when the front and rear shrouds are enlarged, the area of the protrusion in contact with the inner bottom of the groove increases, so when manufacturing, the end face of the blade must be placed inside the groove. Since the applied pressure against the bottom becomes large, the blades are deformed and the width of the water passage of the pump impeller increases, which is a drawback. Furthermore, if protrusions are provided intermittently on the end surface of the blade, when the end surface of the blade is ultrasonically welded to the inner bottom of the groove, the gap between the blade and the inner bottom of the groove will be reduced.
This method has the disadvantage that it is impossible to prevent water from leaking due to the pressure difference between the protrusions provided intermittently and between the protrusions provided intermittently.

SUMMARY OF THE INVENTION In view of the above drawbacks, an object of the present invention is to provide a pump impeller that has little variation in the width of the water passage and can prevent water leakage even when the front and rear shrouds are enlarged.

[Means to solve the problem]

The above purpose is to install a front shroud made of synthetic resin,
a rear shroud made of synthetic resin disposed opposite to the front shroud; a vane portion provided on either the front shroud or the rear shroud and having a hollow portion; A pump impeller comprising a recessed groove provided on either one of the blades and into which the protruding end of the blade is inserted, and the blade is ultrasonically welded to the inner bottom of the groove. provided intermittently on the end surface, and
The blade portion is located between a protrusion that is dissolved by ultrasonic waves and the intermittently provided protrusion, and is lower in height than the protrusion, and when the protrusion is fixed in the groove. This can be achieved by providing a protrusion that prevents leakage caused by the pressure difference that occurs before and after.

[Effect]

According to the pump impeller of the present invention, when ultrasonic waves are applied to the front shroud and the rear shroud while the protrusions provided intermittently on the end face of the impeller are pressed against the inner bottoms of the opposing concave grooves, the intermittently provided protrusions The protrusion softens and eventually welds to the inner bottom of the groove, thus integrating the front shroud and the rear shroud.

While the intermittent protrusions soften and weld to the inner bottom of the groove, the air inside the hollow part of the blade escapes from below the low protrusions between the intermittent protrusions. run away. Therefore, since the air in the hollow portion of the blade portion is not compressed, ultrasonic welding of the intermittently provided protrusions and the inner bottom of the groove can be easily performed.

Moreover, when the intermittent protrusions are ultrasonically welded to the inner bottom of the groove, the low protrusions between the intermittent protrusions come into contact with the inner bottom of the groove, causing the blades to move forward and backward. Prevents water leakage caused by the resulting pressure difference.

Furthermore, since the protruding end of the blade is inserted into the groove, it is easy to position the front shroud 1 and the rear shroud 6 during ultrasonic welding, and welding defects due to micro vibrations caused by the ultrasonic wave. , the two can be completely integrated without causing any misalignment of the axes, increasing the welding strength.

Furthermore, the end surface of the vane can be provided with protrusions 5 intermittently within the minimum range that can withstand the peeling force that occurs during operation, startup, or stoppage of the pump impeller. Even if the front and rear shrouds are enlarged, the force to press against the inner bottom of the groove, that is, the applied pressure during ultrasonic welding work, can be kept to an appropriate minimum size, so there is no need to apply more pressure than necessary. As a result, the blade portion is not deformed, and variations in the width of the water passage can be suppressed.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 6.

First, a front shroud 1 made of synthetic resin is provided with a large number of blades 3 protruding from its rear surface so as to form water passages 2 extending radially from the center. A hollow portion 4 is formed inside the blade portion 3. Protrusions 5 are provided intermittently on the rear end surface of the blade portion 3 within a range where sufficient peel strength can be ensured so as to be dissolved by ultrasonic waves. The tips of the protrusions 5 are made at acute angles so that they are in approximate line contact, since the smaller the area of the temperature rise part when vibration is applied by ultrasonic waves, the easier it is to melt. on the other hand,
The rear shroud 6 made of synthetic resin is provided with a groove 7 at a position corresponding to the blade part 3 integrally formed in the front shroud 1 into which the protruding end 3a of the blade part 3 is inserted.

Furthermore, the blade portion is provided with protrusions 5a which are intermittently provided and whose height is lower by δ. Protrusion 5a
are provided so as to connect the protrusions 5 provided intermittently, and the protrusions 5 provided intermittently are provided on the inner bottom of the groove 7.
is in contact with the inner bottom of the groove 7 when welded by ultrasonic waves.

In the above configuration, as shown in FIGS. 3 and 4, when ultrasonic vibration is applied while the protrusion 5 of the front shroud 1 is pressed against the inner bottom of the groove 7 of the rear shroud 6, the protrusion 5 The front shroud 1 and the rear shroud 6 are melted as shown in FIGS. 5 and 6.
Fasten as shown. According to such a pump impeller made of synthetic resin, the protrusions 5 are provided intermittently, and the protrusions 5a having a low height are provided between the protrusions 5, so that the protrusions 5 accumulate in the hollow portion 4 during ultrasonic welding. Ultrasonic welding can be easily performed because the air can be released from below the projections 5a to the outside of the blade portion 3 without being compressed. Furthermore, since welding is performed within the concave groove 7, the front shroud 1 and the rear shroud 6 can be easily positioned during ultrasonic welding, and there is no welding failure or misalignment of the axis due to micro vibrations caused by the ultrasonic waves. , the two can be completely integrated and the welding strength can be increased.

In addition, the protrusions 5 may be provided intermittently within a range that sufficiently satisfies the peeling force generated during operation, startup, or stoppage of the pump impeller, and the ultrasonic application time may be adjusted to suit the outer diameter of the impeller. Can be welded under appropriate welding conditions such as applied pressure. Therefore, deterioration of the base material can be prevented, and deformation of the impeller due to applied pressure can also be prevented, and variations in the width dimension of the water passage 2 of the impeller are reduced, resulting in stable water pumping performance.

Furthermore, after the ultrasonic welding is completed, the protrusion 5a comes into contact with the inner bottom of the groove 7, so there is no gap between the end surface of the blade part 3 and the inner bottom of the groove 7, so that some pressure is generated before and after the blade part 3. It is possible to reliably prevent water leakage that would occur due to the difference.

In this embodiment, the blade portion 3 is molded integrally with the front shroud 1, but the same effect can of course be obtained by molding the blade portion 3 integrally with the rear shroud 6 and providing the groove 7 in the front shroud 1. It is.

〔Effect of the invention〕

According to the present invention, the end face of the blade portion includes protrusions that are disposed intermittently and are dissolved by ultrasonic waves, and protrusions that are disposed between the protrusions that are disposed intermittently and that are disposed on the end face of the blade portion. Since the height is low and the protrusion is provided to prevent water leakage caused by the pressure difference between the front and rear of the blade when the protrusion is fixed in the groove, the front and rear shrouds can be greatly reduced. Even if it is shaped, a pump impeller with excellent productivity can be obtained, which can be manufactured with little variation in the width dimension of the water passage, and can prevent water leakage.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an embodiment of the pump impeller of the present invention, Fig. 2 is a sectional view taken along the - line of Fig. 1, and Fig. 3 is a sectional view taken along the - line of Fig. 2 during manufacture. Fig. 4 is a cross-sectional view taken along line - of Fig. 2 during manufacture, Fig. 5 is a cross-sectional view taken along line - of Fig. 2 in the completed state of manufacture, Fig. 6
The figure is a sectional view taken along the line - in FIG. 2.
1...Front shroud, 2...Water passage, 3...Blade part,
4...Hollow part, 5, 5a...Protrusion, 6...Rear shroud, 7...Concave groove.

Claims (1)

[Claims] 1 A front shroud 1 made of synthetic resin, a rear shroud 6 made of synthetic resin disposed opposite to this front shroud 1, and a hollow structure provided on either the front shroud 1 or the rear shroud 6, and which is hollow. The blade portion 3 is provided with a recessed groove 7 provided in either the front shroud 1 or the shroud 6 and into which the protruding end portion 3a of the blade portion 3 is inserted.
In the pump impeller which is formed by ultrasonically welding to the inner bottom of the concave groove 7, the end face of the blade part 3 has protrusions 5 which are disposed intermittently and which are dissolved by ultrasonic waves, It is located between the protrusions 5 that are provided in the same manner, and is lower in height than the protrusions 5, and when the protrusions 5 are fixed in the grooves 7, due to the pressure difference that occurs before and after the blade part 3. A pump impeller characterized in that it is provided with a protrusion 5a for preventing water leakage.