KR960010262B1 - Double crank - Google Patents

Abstract

The double crank, applicable to various industrial machines, includes two crank shafts on the upper and lower part to implement a powerful stroke with a minimum energy and reduce the inefficiency in the conventional crank driver. The double crank comprises: a 1st crank shaft(6) and a 2nd crank shaft(9) rotatably axled by a rotational drive member; a connecting rod(20) connecting the two crank shafts(6,9); a slide shaft hole(22), formed on a frame(21) and making the 2nd crank shaft(9) rotatably move up/down within a small width.

Description

Double Cranks for Industrial Machinery

1 is a front view showing one preferred embodiment of the present invention.

2 is a side view showing one preferred embodiment of the present invention.

3 is a perspective view of the main portion of the present invention.

4 is a vector exploded view for explaining the principle of the present invention,

(A) Vector resolution diagram of a conventional single crank.

(B) is the balance of power.

(C) is a vector exploded view of the double crank of the present invention.

5 is a side view for explaining the principle of the present invention,

A side view of a conventional single crank.

(B) is a vector exploded view of the double crank of the present invention.

(C) is the power balance of the second crankshaft.

* Explanation of symbols for main parts of the drawings

1: die, 2: punch,

3: motor, 4: reducer,

4 ': drive shaft, 5: belt pulley,

6: 1st crankshaft, 7: belt pulley,

8: belt, 9: secondary crankshaft,

10: spur gear, 11: connecting shaft,

12: spur gear, 13: chain sprocket,

14: second connecting shaft, 15: chain sprocket,

16: chain, 17: chain sprocket,

18: chain sprocket, 19: chain,

20: connecting rod, 21: frame,

22: slide shaft hole, 23: connecting rod.

The present invention relates to a crank drive mechanism that can be applied to various industrial machines, and more particularly to a double crank having a first and second crankshaft up and down.

In general, a crank drive mechanism for converting rotational motion into linear motion in various industrial machines connects an operating member (for example, a punch or a die) to an eccentrically installed crank arm with a connecting rod, so that the connecting rod is as straight as the eccentric width of the crank arm. In the crank drive mechanism using a single crankshaft, the driving energy of the corresponding crankshaft is required according to the stroke of the linear reciprocating motion of the connecting rod. Consumption of energy sources was also significant due to the need for increased output.

Accordingly, the present invention provides a drive means employing a double crank which can eliminate the inefficiency of energy use of the existing crank drive mechanism as described above, and can freely use a large stroke with minimum energy. will be.

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention.

1 is a front configuration diagram showing a preferred embodiment of the present invention, FIG. 2 is a side configuration diagram, and FIG. 3 is a perspective view showing such an embodiment. The workpiece on the lower die 1 is formed by the punch 2 or the like. In various industrial machines such as presses for cold pressing or hot forging of a predetermined work, the upper motor 3 is connected to the reducer 4, and a belt pulley is mounted on the drive shaft 4 ′ of the reducer 4. (5) is inserted into the belt pulley (7) and the belt (8) fixed to one end of the primary crankshaft (6) to allow the interconnection drive, and the lower side of the primary crankshaft (6) with a predetermined width The secondary crankshaft 9 is installed so as to rotate while lifting up a predetermined width.

In order to drive the secondary crankshaft 9, one end of the primary crankshaft 6 is inserted into the spur gear 10 so as to be interlocked with the spur gear 12 on the connecting shaft 11. The connecting shaft 11 also inserts the chain sprocket 13 so as to be connected and driven by the chain sprocket 15 and the chain 16 inserted on the second connecting shaft 14, and the second connecting shaft (14) is also inserted into a separate chain sprocket 17 to drive the chain sprocket 18 and chain 19 inserted into the secondary crankshaft (9).

The driving means of the first and second crankshafts 6 and 9 can be replaced or changed in design as well as the various driving means as well as the illustrated means.

The first and second crankshafts 6 and 9 are connected to each other by connecting rods 20 so that they can be interlocked with each other. However, the second and second crankshafts 9 rotate while lifting and lowering on the frame 21. The shaft hole is formed in the slide shaft hole 22 to be formed.

The crank pin of the secondary crankshaft 9 is connected to the punch 2 using the connecting rod 23.

The present invention, which can be configured as described above, can be applied to various industrial machines to provide about twice as much output as conventional crank drive mechanisms using motors of the same output, in terms of efficient use of energy. As it can provide more than expected, it will be described in detail;

In the device drive of the present invention, when the reducer 4 is driven by the driving of the motor 3 and the driving shaft 4 'is rotated, it is inserted into the belt pulley 5 and the primary crankshaft 6 inserted therein. The belt pulley 7 is connected to the belt 8 so that the primary crankshaft 6 is driven, and the connecting rod 20 connected to the crank pin of the primary crankshaft 6 moves up and down. Done.

Then, the sprocket gear 12 on the connecting shaft 11 and the chain sprocket 13 on the connecting shaft 11 are simultaneously rotated by the spur gear 10 engaged with the spur gear 10 inserted into one side of the primary crankshaft 6. The chain sprocket 15 on the second connecting shaft 14 connected by (16) is rotated so that another chain sprocket 17 pivoted on the second connecting shaft 14 is rotated to the chain 19. The chain sprocket 18 on the connected secondary crankshaft 9 rotates so that the secondary crankshaft 9 also rotates, and the connecting rod 23 connected to the crank pin of the secondary crankshaft 9 moves up and down. As the punch 23 punches a workpiece placed on the lower die 2 to forge a product, the double crank drive mechanism of the present invention by this operation is more clearly demonstrated by the following equation.

The case where the frictional force is ignored along with the fourth and fifth degrees and the case where the frictional force is considered will be described as an example.

1. When frictional force is not taken into account

(1) single crank

In Figure 4 (a)

θ = 180- (90 + α + β) = 90- (α + β)

d = R · cosθ = R · cos ｛90− (α + β)｝ = Rsin (α + β). … … … … … (One)

Since the force P in the vertical direction is a component of the y direction of the force F, in FIG.

P = Fcosα⇒ … … … … … … … … … … … … … … … … … … … (2)

The moment is the product of the acting force multiplied by the vertical distance from the center of the moment to the force. So the moment is

M = F × d... … … … … … … … … … … … … … … … … … … … … … … … … … … … (3)

Substituting equations (1) and (2) into equation (3)

XRsin (α + β)

If we express about P

∴ … … … … … … … … … … … … … … … … … … … (4)

Therefore, the vertical force of a single crank is calculated as shown in equation (4).

(2) double crank

In the case of the double crank, as shown in FIG. 4 (C), since the two cranks are driven by one motor, the rotation moment is divided into 1/2 of the single crank. The double crank has a structure for simultaneously driving two cranks having a radius of 1/2 of a single crank.

Therefore, since one motor drives two cranks, the rotation moment of each crank And the radius is to be.

(Actually correct It's not divided, but it's almost the same.)

Therefore, instead of M, the result of equation (4) , Instead of R If you substitute,

P ₁ = P ₂ = · = … … (5)

The force from the crank, one of the double cranks, is equal to the force from a single crank.

The total force F1 is the sum of P1 and P2.

P = P ₁ + P ₂ = 2M

Therefore, compared with Equation (4), it can be seen that twice as much force as a single crank.

2. Efficiency comparison when considering friction

The weight of FIG. 5 ( _a , _b , _{c) is} referred to as m _a , m _b , m _c , respectively.

Moment reduction due to friction on the axis of rotation can be represented by f = μ.m.g.r.

(Μ: friction coefficient, m: weight acting on the axis, g: gravitational acceleration, r: radius of the axis)

(1) single crank

Moment reduction due to friction of the shaft portion

f = μ (m _a + m _c ) gr

The actual moment of action

M _R = Mf = M-μ (m _a + m _c ) gr

So the vertical force is

P = M _R = ｛M-μ (m _a + m _c ) gr｝ … … (6)

(2) double crank

In the case of a double crank, a frictional part is a slide portion in which two shafts and a second crank reciprocate up and down.

The amount of moment decrease due to the frictional force in the first axis

f1 = μ (2m _a + m _b + m _c ) gr

The amount of moment reduction due to the frictional force in the second axis

fg = μ (m _a + m _c ) gr

Becomes

Actual moment acting on the 1st axis

M _R1 = M ₁ -f ₁ = M ₁ -μ (2m _a + m _b + m _c ) gr

Actual moment acting on the second axis

M _R2 = M ₂ -f ₂ = M ₂ -μ (m _a + m _c ) gr

Is calculated as

The frictional force of the slide portion in which the second crank moves up and down is as follows. Fig. 5 (c) shows the equilibrium diagram of the force of the part.

The frictional force is the coefficient of friction μ multiplied by the normal force N.

Normal drag

N = P ₁ · sinα

Therefore, the frictional force

_{P 3 = μ · N = μ} · P 1 · sinα

Becomes

The total vertical force is

_{P = P 1 + P 2 -P} 3 = P 1+ P 2 -μ · P 1 · sinα = (1-μ · sinα) P 1 + P 2

= [(1-μ · sinα) ｛M ₁ -μ (2m _a + 2m _b + 2m _c ) gr｝ + ｛M ₂ -μ (m _a + m _c ) gr｝] It is calculated as (7).

3. Actual Application

This time, we substitute the actual data using the formula calculated as above and define the data as follows.

M = 100kgm

m _a = 200 kg, m _b = 200 kg, m _c = 300 kg

μ = 0.05, R = 0.2m, r = 0.15m

α = 10 °, β = 20 °

(1) single crank

Substituting the above data expression (6) into;

P _A = ｛100-0.05 (200 + 300) * 0.15｝ = 947.9kg

(2) double crank

In the case of double cranks, the radii of the moment and crank are 1/2, respectively, and M = 50 and R = 0.1 are substituted into Eq. (7).

P _B = [(1-0.05sin10) ｛50-0.05 (2 * 200 +200 +300) * 0.15｝ + ｛50 -0.05 (200 +300) * 0.15｝]

Find the ratio of double cranks to single cranks;

Therefore, the double crank can be obtained by 1.85 times the force compared to the single crank is clearly confirmed by the above equation.

As described in detail above, the present invention comprises a first and second crankshafts 6 and 9, and the crankshafts 6 and 9 are interconnected rods 20 in a conventional crank drive mechanism. It is a very useful invention that can double the large output with less energy consumption by connecting and driving.

Claims (1)

In crankshaft applied to various industrial machines; Arranging the primary crankshaft 6 and the secondary crankshaft 9 so as to be rotated up and down by rotation driving means; The first and second crankshafts 6 and 9 are connected to each other by using the connecting rod 20, and the shaft holes on the frame 21 of the base body on which the secondary crankshafts are installed are formed as slide shaft holes 22, A double crank for an industrial machine, characterized in that the car crankshaft (9) is configured to be rotated up and down a predetermined width.